[style-extension] Remove the expression getter/setters for source properties

[pengdev]

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Fixes: < Link to related issues that will be fixed by this pull request, if they exist >

Pull request checklist:

• Briefly describe the changes in this PR.
• Include before/after visuals or gifs if this PR includes visual changes.
• Write tests for all new functionality. If tests were not written, please explain why.
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Summary of changes

Currently we generate expression getter/setters for source properties, however, capturing from gl-native team, sources don't support expressions at all.

We need to remove the expression getter/setters for source properties.

User impact (optional)

These APIs were not supported or usable, usage of these APIs could be safely removed from the downstream projects.

[kiryldz]

@pengdev glad to see regular CI has passed, I kicked off style test manually.