fix: incorrectly forcing a language constituency selection for a CC page (resolves #2031)

[jobara]

Resolves #2031

• Ignores empty language selections
• Saves language consistency for community org community connectors
• Expands validation error tests for individuals

Prerequisites

If this PR changes PHP code or dependencies:

• [x] I've run composer format and fixed any code formatting issues.
• [x] I've run composer analyze and addressed any static analysis issues.
• [x] I've run php artisan test and ensured that all tests pass.
• [x] I've run composer localize to update localization source files and committed any changes.

If this PR changes CSS or JavaScript code or dependencies:

• [ ] I've run npm run lint and fixed any linting issues.
• [ ] I've run npm run build and ensured that CSS and JavaScript assets can be compiled.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (6db4d21) 97.93% compared to head (c00abcd) 97.93%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #2143 +/- ## ============================================ - Coverage 97.93% 97.93% -0.01% - Complexity 2146 2147 +1 ============================================ Files 333 333 Lines 9804 9798 -6 ============================================ - Hits 9602 9596 -6 Misses 202 202 ```

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