STRATCONN-6005 - [Amplitude] - library and platform hard coded issue

[joe-ayoub-segment]

See https://twilio-engineering.atlassian.net/browse/STRATCONN-6005 for description of issue.

This PR makes it possible for customers to provide a mapping for the library and platform fields. Before this PR there was hard coded logic in place which restricted customers from doing so.

This PR adds 2 new fields:
library2 and platform2.

It hides the existing library and platform fields.

Logic is introduced to allow for legacy behavior to be maintained for customers who already have the integration configured - but allows for new instances of the Integration to work in a way customers expect.

Testing

Unit tests added.
Tested in Staging. See JIRA ticket comment for video and screenshots of testing. https://twilio-engineering.atlassian.net/browse/STRATCONN-6005

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.96%. Comparing base (7c66b14) to head (4acf2cf).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3437   +/-   ##
=======================================
  Coverage   79.95%   79.96%           
=======================================
  Files        1223     1223           
  Lines       22691    22701   +10     
  Branches     4504     4511    +7     
=======================================
+ Hits        18143    18153   +10     
  Misses       3717     3717           
  Partials      831      831           

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