[MM-63007][MM-63004][MM-63020][MM-63009][MM-63008] More accessibility fixes around Search (#31409)

* [MM-63008] Make collapse button on search bar an actual button

* [MM-63004][MM-63020] Convert search box to floating-ui, fix some of the roles and labels that were incorrect

* [MM-63009] Add radiogroup and radio roles to the search box types

* [MM-63007] Ensure search box reads out number of results with suggestion items

* Fix playwright tests

* PR feedback

* Remove floating ui overlay

* Remove unnecessary .first() by being more specific about the search box

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Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/integration/channels/keyboard_shortcuts/ctrl_cmd_l_set_message_focus_spec.js

@@ -43,7 +43,7 @@ describe('Keyboard Shortcuts', () => {
     it('MM-T1250 CTRL/CMD+SHIFT+L - Set focus to center channel message box (with SEARCH RHS open)', () => {
         // # Search
         cy.uiGetSearchContainer().click();
-        cy.uiGetSearchBox().first().type('test{enter}');
+        cy.uiGetSearchBox().type('test{enter}');
 
         // * Wait for the RHS to open and the search results to appear
         cy.contains('.sidebar--right__header', 'Search Results').should('be.visible');