Add new capabilty to make a form field editable

[trymebytes]

Fixes #227

To test, kindly create the events that satisfies the conditions listed in the issue #227

1. Create an event that starts in the future, you would only be able to edit the following;
   Title
   Description
   Dates

A. Edit the event created in 1 to start now

2. With no contributions to the event created in A, you would only be able to edit the following;
   Title
   Description
   Dates

3. Add contributions to the event created in A, you would only be able to edit the following;
   Title
   Description
   Extend the end date

B. Find or create an event that has ended

5. Within 0-1 hour after the event has ended, you would only be able to edit the following;
   Title
   Description
   Extend the end date

6. After one hour after the event has ended, you would only be able to edit the following;
   Description

[psrpinto]

Looks great! Got a few comments

[trymebytes]

Thank you for catching these, I'll address them.

[psrpinto]

Code looks good 👍

However, there's an issue when trying to update an event that is active now and has stats (step A.3 in the testing instructions), I get:

Error: Invalid time zone.

[trymebytes]

Thanks for testing, taking another look.