docs(lock): clarify LockContext docs and modernize implementation

[joshtrichards]

Summary

Improve LockContext documentation and make the implementation more concise.

Changes

• clarify the class docblock and constructor parameter docs
• document getType(), getOwner(), and __toString() more clearly
• switch to constructor property promotion
• mark properties as readonly
• simplify __toString() using match and sprintf()

Notes

This is a documentation/cleanup change only and is not intended to change lock behavior.¹

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

Footnotes

1. Technically I did drop an extra space in the __toString() output. ↩