Always deactivate license key after AJAX request

[jakejackson1]

Description

Regardless of the outcome of the API request, always remove the license key from the database. This prevents UX issues if a license is manually deactivated from the GravityPDF.com account.

Update the error message to let a user know the license may not have been deactivated successfully, with a link to their account.

Resolves #1432

Checklist:

• [x] I've tested the code.
• [x] My code is easy to read, follow, and understand
• [ ] My code follows the accessibility standards.
• [ ] My code has proper inline documentation / docblocks.

Additional Comments

[codecov[bot]]

Codecov Report

Merging #1468 (85a0e84) into development (4d79680) will increase coverage by 17.54%. The diff coverage is n/a.

:exclamation: Current head 85a0e84 differs from pull request most recent head 13db133. Consider uploading reports for the commit 13db133 to get more accurate results

@@                Coverage Diff                 @@
##             development    #1468       +/-   ##
==================================================
+ Coverage          75.75%   93.30%   +17.54%     
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  Files                243       57      -186     
  Lines              12842     1464    -11378     
  Branches             370      370               
==================================================
- Hits                9729     1366     -8363     
+ Misses              3105       90     -3015     
  Partials               8        8               

see 186 files with indirect coverage changes