move content to first place

[InesaFitsner]

Description

Test Code

# Test code for the review of this PR

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

Enhancements:

• Rearranged the order of class attributes to move 'content' to the first place

[ndonkoHenri]

Had it fixed in here actually: https://github.com/flet-dev/flet/pull/5265/files#diff-b4bbd631d795779fdb8abac5dfacb4e9cf60c5bcfa61b97a8fbb46bfbc9a46d2

[FeodorFitsner]

Closing in favor of #5265