refactor: replace all lodash.* dependencies with es-toolkit/compat

[debuggingfuture]

Description

Replacing lodash.* with es-toolkit/compat

Replacements:

• lodash.camelcase / kebabcase / snakecase / startcase / upperfirst → es-toolkit/compat in @commitlint/ensure (case helpers)
• lodash.mergewith → es-toolkit/compat:
  • mergeWith (with customizer) in @commitlint/resolve-extends
  • merge (no customizer) in @commitlint/load, @commitlint/config-patternplate, and the cli test helper

Notes:

• For strings handling, it's noted chore: update dependency husky to v1 #462 revert kasi change due to non-Latin subject-case regressions
  use of compat mode es-toolkit/compat should pass them
• es-toolkit/compat's mergeWith always treats the last positional argument as the customizer, unlike lodash's createAssigner which detects function-typed customizers. Call sites that passed objects (no customizer) are switched to es-toolkit's variadic merge to preserve behavior.

Motivation and Context

For improving performance, minimizing dependencies and supply chain attack vectors.
Reference: https://e18e.dev/docs/replacements/lodash-underscore

How Has This Been Tested?

Test results: 1185/1185 tests across 90 files pass, including the Cyrillic / Chinese / Arabic / Hebrew / mixed-script subject-case cases that broke under kasi.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[escapedcat]

Thanks!