MM-62288 - add e2e to RHS focus functionality (#29655)

* MM-62288 - add e2e to RHS focus functionality

* remove describe only

* Use existence check before closing RHS

* modify close rhs function to not fail when rhs is not opened

* avoid body to not get found

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

e2e-tests/cypress/tests/integration/channels/messaging/message_reply_bot_post_spec.js

@@ -88,7 +88,7 @@ describe('Messaging', () => {
         });
     });
 
-    it.skip('MM-T91 Replying to an older post by a user that has no content (only file attachments)', () => {
+    it('MM-T91 Replying to an older post by a user that has no content (only file attachments)', () => {
         // # Get yesterdays date in UTC
         const yesterdaysDate = Cypress.dayjs().subtract(1, 'days').valueOf();