refactor: Fix serialization of conf object

[itsomri]

Description

This PR makes the KAI operator use the scheduler conf object instead of an internal object. It also fixes serialization to and from YAML by using the k8s yaml package and time.Duration types, instead of the native go int representation. Behavior should remain the same.

Checklist

Note: Ensure your PR title follows the Conventional Commits format (e.g., feat(scheduler): add new feature)

• Self-reviewed
• Added/updated tests (if needed)
• Updated CHANGELOG.md (if needed)
• Updated documentation (if needed)

Breaking Changes

N/A

Additional Notes

N/A

[github-actions]

Merging this branch will decrease overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/NVIDIA/KAI-scheduler/pkg/env-tests/timeaware	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler	78.83% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache	35.14% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api	29.85% (-31.69%)	💀 💀 💀
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/fake	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/prometheus	19.15% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util	80.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/NVIDIA/KAI-scheduler/pkg/env-tests/timeaware/timeaware.go	0.00% (ø)	150	0	150
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/resources_for_shard.go	87.76% (ø)	98	86	12
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/scheduler.go	52.94% (ø)	34	18	16
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/cache.go	53.79% (ø)	132	71	61
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/defaults.go	50.00% (-5.88%)	30 (-4)	15 (-4)	15	👎
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/interface.go	13.51% (-86.49%)	37 (+32)	5	32 (+32)	💀 💀 💀 💀 💀
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/fake/fake_with_history.go	0.00% (ø)	51	0	51
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/prometheus/prometheus.go	19.15% (ø)	94	18	76
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf/scheduler_conf.go	0.00% (ø)	15	0	15
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util/scheduler_conf_util.go	80.00% (ø)	40	32	8

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/resources_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/scheduler_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/usage_params_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util/scheduler_conf_util_test.go

[github-actions]

Merging this branch will decrease overall coverage

Impacted Packages	Coverage Δ	🤖
github.com/NVIDIA/KAI-scheduler/pkg/env-tests/timeaware	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler	78.83% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache	35.14% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api	29.85% (-31.69%)	💀 💀 💀
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/fake	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/prometheus	19.15% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf	0.00% (ø)
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util	80.00% (ø)

---

Coverage by file

Changed files (no unit tests)

Changed File	Coverage Δ	Total	Covered	Missed	🤖
github.com/NVIDIA/KAI-scheduler/pkg/env-tests/timeaware/timeaware.go	0.00% (ø)	150	0	150
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/resources_for_shard.go	87.76% (ø)	98	86	12
github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/scheduler.go	52.94% (ø)	34	18	16
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/cache.go	53.79% (ø)	132	71	61
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/defaults.go	50.00% (-5.88%)	30 (-4)	15 (-4)	15	👎
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/interface.go	13.51% (-86.49%)	37 (+32)	5	32 (+32)	💀 💀 💀 💀 💀
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/fake/fake_with_history.go	0.00% (ø)	51	0	51
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/prometheus/prometheus.go	19.15% (ø)	94	18	76
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf/scheduler_conf.go	0.00% (ø)	15	0	15
github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util/scheduler_conf_util.go	80.00% (ø)	40	32	8

Please note that the "Total", "Covered", and "Missed" counts above refer to code statements instead of lines of code. The value in brackets refers to the test coverage of that file in the old version of the code.

Changed unit test files

• github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/resources_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/operator/operands/scheduler/scheduler_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/scheduler/cache/usagedb/api/usage_params_test.go
• github.com/NVIDIA/KAI-scheduler/pkg/scheduler/conf_util/scheduler_conf_util_test.go