Create setup and ecr get-login migrate-v2 checker

[aemous]

Description of changes:

• Create code architecture for migration readiness feature.
• Implement ecr get-login breaking change checker.
• Add new-change file.

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[AndrewAsseily]

Looks like we have a couple of CI tests that need attention

[codecov-commenter]

Codecov Report

❌ Patch coverage is 58.62069% with 12 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (debug-migration@d6685a8). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
awscli/clidriver.py	36.84%	12 Missing ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##             debug-migration    #9703   +/-   ##
==================================================
  Coverage                   ?   93.27%           
==================================================
  Files                      ?      210           
  Lines                      ?    16833           
  Branches                   ?        0           
==================================================
  Hits                       ?    15701           
  Misses                     ?     1132           
  Partials                   ?        0           

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