fix: Enable TextButton style and full-width Dropdown

[7576457]

Description

Made TextButton style actually work and allowed Dropdown to expand fully

issues:

• bug: ButtonStyle in TextButton has no effect #6047
• bug: [Flet 0.80.1] How can i expand a dropdown to all horizontal available space ? #6044

Type of change

• 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)
• This change requires a documentation update

Checklist

• I signed the CLA.
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing tests pass locally with my changes
• I have made corresponding changes to the documentation (if applicable)

Screenshots

Additional details

Summary by Sourcery

Fix button styling and dropdown layout behavior to honor configured styles and horizontal expansion.

Bug Fixes:

• Make button controls correctly apply the configured style from control properties.
• Allow dropdown controls to fully expand horizontally when the expand property is set.

[sourcery-ai]

We've reviewed this pull request using the Sourcery rules engine

[ndonkoHenri]

LGTM, thanks! 😄