Closes: [BS-2909](https://linear.app/affine-design/issue/BS-2909/新增highlighter)
### What's Changed!
Currently the highlighter tool is very similar to brush, but for the future, it's a standalone module.
* Added `Highlighter` element model
* Added `Highlighter` tool
* Added `Highlighter` entry to the global toolbar
### What Changes
- Fixed incorrect edgeless viewport display in peek view
- Moved page block viewport fit animation logic from `EdgelessRootBlockComponent` to note config extension
- Disabled page block viewport fit animation in peek view, using default `fitToScreen` instead
- @doodlewind Fixed viewport resizing issues by adding a immediate update mechanism to ensure proper rendering during peek view operations. The setViewportByBound is only called once during peek view initialization, so there are barely perf overhead.
- Updated related test cases
- Refactored peek view test cases to make them clearer and more reliable
- Added new test helper function `getViewportBound` for getting viewport boundary information