Complete WRITE_PARALLEL migration: expose from MAPL3, remove from MAPL2

[tclune]

As part of the base3g migration (see PR for commit ee68795), WRITE_PARALLEL was added to base3g/FileIO.F90 (mapl3g_FileIO) but intentionally not re-exported from base3g/API.F90 yet.

This is because clients that use MAPL and use MAPL2 simultaneously would see ambiguous interfaces (write_parallel_string vs write_parallel_string_0).

Steps to complete the swap

1. Migrate all remaining MAPL2 clients that call WRITE_PARALLEL to use MAPL instead
2. Add WRITE_PARALLEL back to base3g/API.F90 public exports
3. Remove WRITE_PARALLEL from MAPL2's top-level re-export (or from FileIOSharedMod entirely)

Related

• base3g/FileIO.F90 — new home for string variant of WRITE_PARALLEL
• base/FileIOShared.F90 — old home (full generic with numeric variants, ArrDescr etc.)
• Issue Are _CRAY/_CRAYT90 guards in MAPL_MemUtils still needed? #4755 — Cray guards in MAPL_MemUtils

[tclune]

Resolved by PR #4773 — WRITE_PARALLEL migration complete.