Fix --output text --query emitting a stray None for the pagination resume hint

[Abuhaithem]

Fixes: #10449

Description

When --output text is combined with --query and a paginated response is
truncated (for example via --max-items), the CLI printed a stray None line:

$ aws iam list-users --max-items 1 --output text --query 'Users[].UserName'
alice
None        # <-- bug

TextFormatter emits the NEXTTOKEN resume-token hint through
_format_response, which applies the user's --query expression. Evaluating a
data expression against the hint object
{"NextToken": {"NextToken": "<token>"}} returns None, and that None was
written to stdout, corrupting text/scripted output.

The resume-token hint is pagination metadata, not part of the queried result
set, so it is now rendered directly via text.format_text(...), bypassing
--query:

$ aws iam list-users --max-items 1 --output text --query 'Users[].UserName'
alice
NEXTTOKEN	<token>   # hint preserved, no stray None

Scope

• TextFormatter only. The JSON and Table formatters aggregate the full result
  and apply --query once to the whole response, so they were never affected.
• No behavior change when --query is absent, and none for non-truncated
  responses (no resume token, so the branch is not entered).

Changes

• awscli/formatter.py — render the resume-token hint with text.format_text
  instead of _format_response so the global --query is not applied to it.
• tests/unit/output/test_text_output.py — add TestTextPaginationResumeToken
  with two end-to-end functional tests (via BaseAWSCommandParamsTest):
  • the resume hint is still emitted without --query;
  • with --query, the queried data renders, the NEXTTOKEN hint is
    preserved, and no None line appears.
• .changes/next-release/bugfix-text-output-pagination.json — changelog entry.

Testing

$ python -m pytest tests/unit/output/test_text_output.py

• The new --query test fails on develop (reproduces the bug) and passes
  with this change.
• Existing tests/unit/output/, tests/unit/test_text.py, and
  tests/functional/kinesis/test_list_streams.py continue to pass.

Checklist

• Bug fix includes tests (per CONTRIBUTING.md).
• Targets the develop branch.
• Code follows PEP 8 and is consistent with the surrounding module.
• Cross-platform; no platform-specific behavior introduced.
• Changelog entry added under .changes/next-release/.