[MM-62986][MM-63011][MM-63013][MM-63014][MM-63018] Various accessibility fixes around login, account creation and MFA setup (#30847)

* [MM-62986] Ensure focus goes back to the inputs after an error for Login/Create Account/MFA

* [MM-63011] Show outline on Mattermost logo link when focused

* [MM-63018] Remove tabindex from the login/signup cards and use <form> element for submit

* [MM-63014] Toggle aria-label when show/hide password is pressed

* [MM-63013] Mention the field name when showing an error message about the password field

* Fix lint

* Update screenshots and fix tests

* Update screenshots and fix tests

* Fix tests

* Update webapp/channels/src/components/mfa/setup/setup.tsx

Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

* update screenshots

---------

Co-authored-by: yasserfaraazkhan <attitude3cena.yf@gmail.com>
Co-authored-by: Harrison Healey <harrisonmhealey@gmail.com>

e2e-tests/cypress/tests/integration/channels/account_settings/security/password_spec.ts

@@ -80,8 +80,8 @@ describe('Profile', () => {
         // # Save
         cy.uiSave();
 
-        // * Verify for error message: "Must be 5-72 characters long."
-        cy.get('#clientError').should('be.visible').should('have.text', 'Must be 5-72 characters long.');
+        // * Verify for error message: "Your password must be 5-72 characters long."
+        cy.get('#clientError').should('be.visible').should('have.text', 'Your password must be 5-72 characters long.');
     });
 
     it('MM-T2084 Password: Cancel out of password changes causes no changes to be made', () => {