fix(richtext-*): fix client features were not loaded properly, improve performance of LexicalProvider, slate cell component was non-functional, support richtext adapter Cell RSCs

[AlessioGr]

Description

schemaPath in the Cell components of richText was empty, as it was not passed through useFieldProps there. Moved it to cellComponentProps. Now that the clientFeature/componentMap paths have proper schemaPaths again, stuff is working again.

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Type of change

• Chore (non-breaking change which does not add functionality)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Change to the templates directory (does not affect core functionality)
• Change to the examples directory (does not affect core functionality)
• This change requires a documentation update

Checklist:

• I have added tests that prove my fix is effective or that my feature works
• Existing test suite passes locally with my changes
• I have made corresponding changes to the documentation