[SG-483] Trial Initiation Cleanup (#4064)

* Remove 'showTrial' feature flag

* Replace Register component with trial and redirect trial routes to register

* Shore up fallback logic for bad params

* Remove register component that is no longer used

* Adjust register form margin top

* Update unit tests for new param handling

* Use enums for org names and add missing org routing

* Add new tests and fix existing flaky ones

* Use an enum for layouts

apps/web/src/utils/flags.ts

@@ -9,7 +9,6 @@ import {
 // required to avoid linting errors when there are no flags
 /* eslint-disable-next-line @typescript-eslint/ban-types */
 export type Flags = {
-  showTrial?: boolean;
   secretsManager?: boolean;
   showPasswordless?: boolean;
 } & SharedFlags;