Fixes ShapedTextRun drawing

[Gillibald]

What does the pull request do?

This PR reverts some changes related to the BaselineOffset calculation that caused a regression related to render transforms that might be applied to some text rendering.

Before this change a text line was drawn at a common baseline. To make this work the baseline origin of produces GlyphRuns was set to (X,0) and the current matrix was translated to the common baseline.

This change caused rotation transforms to fail because the transform-origin was no longer at the needed position.

To work around this the PR reverts the changes to the baseline origin and the baseline offset calculation is adjusted to translate each run individually to the common baseline.

What is the current behavior?

What is the updated/expected behavior with this PR?

How was the solution implemented (if it's not obvious)?

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/avalonia-docs with user documentation

Breaking changes

Obsoletions / Deprecations

Fixed issues

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0050739-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]

[avaloniaui-bot]

You can test this PR using the following package version. 11.2.999-cibuild0050796-alpha. (feed url: https://nuget-feed-all.avaloniaui.net/v3/index.json) [PRBUILDID]