plan: Add component memoization implementation plan

[mofojed]

Two options for props-based memoization to skip re-renders:
- Option A: @ui.memo decorator (familiar to React devs)
- Option B: @ui.component(memo=True|compare_fn) parameter (cleaner)

Includes:
- API design and implementation details
- MemoizedFunctionElement and Renderer changes
- Unit tests for both options
- Performance benchmarks
- Comparison and recommendation (implement both)

[github-actions]

Pull Request titles must follow the Conventional Commits specification.

Details:

Unknown release type "plan" found in pull request title "plan: Add component memoization implementation plan". 

Available types:
 - feat: A new feature
 - fix: A bug fix
 - docs: Documentation only changes
 - style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
 - refactor: A code change that neither fixes a bug nor adds a feature
 - perf: A code change that improves performance
 - test: Adding missing tests or correcting existing tests
 - build: Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
 - ci: Changes to our CI configuration files and scripts (example scopes: Travis, Circle, BrowserStack, SauceLabs)
 - chore: Other changes that don't modify src or test files
 - revert: Reverts a previous commit

[mofojed]

With this notation we could also write:

memo_parent = ui.memo(parent)