Prepare v0.14.4 release; move internal, top-level functions back to original file

[alancai98]

Description

• Prepares v0.14.4 minor release
• Running the Java API compliance checker showed that moving the internal, top-level functions to a different file in Add additional APIs for async physical plan evaluation #1382 is a "breaking change" from Java perspective (since Java can call internal Kotlin functions). Choosing the conservative approach to move back the internal, top-level functions back to the original file until Decide on Java interop w/ Kotlin top-level functions #1387 is resolved.
  • Following this reversion, I reran the compliance checker, which found no breaking changes.

Other Information

• Updated Unreleased Section in CHANGELOG: [YES]

• Any backward-incompatible changes? [NO]

• Any new external dependencies? [NO]

• Do your changes comply with the Contributing Guidelines
  and Code Style Guidelines? [YES]

License Information

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

Conformance comparison report

	Base (b063e52)	bf86d6a	+/-
% Passing	92.54%	92.54%	0.00%
✅ Passing	5384	5384	0
❌ Failing	434	434	0
🔶 Ignored	0	0	0
Total Tests	5818	5818	0

Number passing in both: 5384

Number failing in both: 434

Number passing in Base (b063e52) but now fail: 0

Number failing in Base (b063e52) but now pass: 0