AmendEvent improvements

[alexeyzimarev]

• Converted AmendEvent to a named function
• Added amend event to the functional service
• Addresses also #283

[github-actions[bot]]

Test Results

  32 files    32 suites   10m 50s :stopwatch: 130 tests 130 :heavy_check_mark: 0 :zzz: 0 :x: 256 runs  256 :heavy_check_mark: 0 :zzz: 0 :x:

Results for commit 870ded5a.