MM-57881 Add metric for the amount of time it takes for the RHS to load a thread (#26970)

* Assure most code dispatches selectPost to open RHS to a thread

* Add measurement of the time it takes to open the RHS

* Reduce unnecessary re-rendering of RhsThread

* Never use Jest's fake timers for the performance API

* Make constants for performance marks and measures

* Add missed constants

webapp/channels/jest.config.js

@@ -19,6 +19,9 @@ const config = {
         'utils/src/**/*.{js,jsx,ts,tsx}',
     ],
     coverageReporters: ['lcov', 'text-summary'],
+    fakeTimers: {
+        doNotFake: ['performance'],
+    },
     moduleNameMapper: {
         '^@mattermost/(components)$': '<rootDir>/../platform/$1/src',
         '^@mattermost/(client)$': '<rootDir>/../platform/$1/src',