Mm 62677 - modal focus management - find channels modal (#29957)

* MM-62312 - modal focus management; revamp quick switch channel modal!

* get quick switch test working

* configure the generic modal to accept refs to focus within and onhide to the origin element

* apply pr feedback, get modal element get autofocus, use id instead of ref

* update more direct channels modal to use generic modal

* fix unit tests and snapshots

* fix unit tests

* fix modal margin top to fit in smaller screens

* fix e2e test

* remove unnecesary onexited extra call

* fix e2e tests

* set correct label

* fix snapshots

* create helper function for sending custom focus event

* migrate quick switch modal to use new approach to focus

* migrate more direct channels modal to new approach

* fix snapshots

* fix types

* fix modal closing behavior

* fix snapshots

* fix cypress tests

* remove only

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

e2e-tests/cypress/tests/integration/channels/bot_accounts/in_teams_and_channels_spec.ts

@@ -55,7 +55,7 @@ describe('Managing bots in Teams and Channels', () => {
             await client.addToTeam(team.id, bot.user_id);
 
             // # Add bot to channel in team
-            cy.uiAddUsersToCurrentChannel([bot.username]);
+            cy.uiInviteUsersToCurrentChannel([bot.username]);
 
             // * Verify system message in-channel
             cy.uiWaitUntilMessagePostedIncludes(`@${bot.username} added to the channel by you.`);