More validation and bug fixes for bulk invites

[ConfuseIous]

• Added check for null data
• Added check for duplicate data in Supabase instead of just locally
• Switched from ForEach loop to for loop to allow for early returns when encountering an error
• Basically #126 but without broken history
• Also integrated the search bars correctly, which is not present in #126

Types of Changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] Issue fix (non-breaking change that addresses existing opened issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Refactoring change (refactoring change must not apply any form of functional change)

Fixes

N/A

Notion Task Coverage

N/A

Checklist

• [x] Related issues linked using fixes #number. / There is no issue fix.
• [x] Unit tests or E2E tests added for any new feature changes. / There is no new feature that requires test.
• [x] Ensured that there's no linter errors.
• [x] Ran the full set of testings and coverage reports exceed 80%. / There is currently no test.
• [x] All Merge Conflicts have been fully resolved.
• [x] Branch is rebased off the target branch.
• [x] This PR is complete and does not have incomplete work that'll break the application.