table: Allow custom DataTable row height

[lurenjia534]

Closes #2352

Description

This pull request fixes DataTable::with_size(px(...)) so custom pixel sizes are used as the table row height.

Previously, Size::table_row_height() only mapped the preset sizes (XSmall, Small, Medium, and Large) to row heights. A custom Size::Size(px) value fell back to the default medium row height (32px), which meant calls such as DataTable::new(&state).with_size(px(48.)) did not change the DataTable header or body row height.

The fix makes Size::Size(px) return its own pixel value from table_row_height(). This keeps DataTable's existing single uniform row-height model intact, so header rows, body rows, loading skeleton rows, scrollbar offsets, page navigation, and stripe filler calculations continue to use the same height source.

This PR also adds a focused regression test for the preset and custom table row height mappings, and updates the English and Chinese DataTable documentation to describe custom row height usage.

Screenshot

Before	After
DataTable::new(&state).with_size(px(48.)) still used the default 32px row height.	DataTable::new(&state).with_size(px(48.)) uses a uniform 48px header and body row height.

How to Test

Run the focused regression test:

cargo test -p gpui-component test_table_row_height

Run the full gpui-component unit test suite:

cargo test -p gpui-component

I also checked the patch for whitespace errors:

git diff --check

Checklist

• I have read the CONTRIBUTING document and followed the guidelines.
• Reviewed the changes in this PR and confirmed AI generated code (If any) is accurate.
• Passed cargo run for story tests related to the changes. Not run; this is a non-visual sizing helper fix covered by unit tests.
• Tested macOS, Windows and Linux platforms performance (if the change is platform-specific). Not platform-specific; no platform-specific performance impact is expected.

[madcodelife]

Thank you, I’ve added a pixel example in the story.

[lurenjia534]

Thank you, I’ve added a pixel example in the story.

Thank!