Allow admin to extend team trial

[knolleary]

Closes #4031

Adds an 'Extend Trial' option under the Admin Tools section of Team Settings:

Dialog lets you pick a new end date

The API prevents setting a date more than 1 year in the future. It can be set to a date in the past, in which case the next time the TrialTask runs (every 30mins) the trial will be ended.

Option only shows for a team in trial (or an expired trial). If they have setup stripe, the option is no longer available.

[codecov]

Codecov Report

Attention: Patch coverage is 86.20690% with 4 lines in your changes missing coverage. Please review.

Project coverage is 78.71%. Comparing base (a04496a) to head (5cb84d8).
Report is 1 commits behind head on main.

Files	Patch %	Lines
forge/ee/lib/billing/index.js	84.21%	3 Missing ⚠️
forge/ee/routes/billing/index.js	90.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4052      +/-   ##
==========================================
+ Coverage   78.58%   78.71%   +0.13%     
==========================================
  Files         284      284              
  Lines       12979    13008      +29     
  Branches     2890     2897       +7     
==========================================
+ Hits        10199    10239      +40     
+ Misses       2780     2769      -11     

Flag	Coverage Δ
backend	78.71% <86.20%> (+0.13%)	⬆️

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