feat: replace all headless UI with react aria equiv

[meinte]

• Switch removed (as not being used)
• Select replaced by React-Aria equiv
• DropdownSelect removed - only in use in Add User page, which is replaced by a bespoke React-Aria select

[meinte]

Just noticing a few sonarcloud issues, Ill have a look at those Monday or Tuesday

[sonarcloud[bot]]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud