Unified Login flow for simple login and trial logins

[jaswinder6991]

• Added navigation to the join page from Hero section's trial accounts button. Similar to how Sign In from the header does it.
• On the join page added logic to either render Login or Create Trial Account using the a simple "from" prop.
• This enables unified onboarding flow. Now users doing simple login or trial account login, both will see the onboarding widget. [Tested]
• Added loading state and error handling for the trial API response.