fix: cred helper refactor for windows

[vsiravar]

Issue #, if available:

Description of changes:

• Refactor credhelper and remove hard-coded paths.
  Testing done:
  Yes, can push to ECR

 cat .\config.json
{"credsStore":"ecr-login"}

PS C:\Users\Administrator> finch build -t test-ecr-from-local .
PS C:\Users\Administrator> finch tag test-ecr-from-local:latest 065363855432.dkr.ecr.us-east-2.amazonaws.com/test-ecr-from-local:latest
PS C:\Users\Administrator> finch tag test-ecr-from-local:latest 065363855432.dkr.ecr.us-east-2.amazonaws.com/test-ecr-from-local:latest^C
PS C:\Users\Administrator> finch push 065363855432.dkr.ecr.us-east-2.amazonaws.com/test-ecr-from-local:latest
INFO[0000] pushing as a reduced-platform image (application/vnd.docker.distribution.manifest.v2+json, sha256:317cda6f2c180388322d9134cf8976aac777a5d6cf1a56161ac22e996a1df051)
manifest-sha256:317cda6f2c180388322d9134cf8976aac777a5d6cf1a56161ac22e996a1df051: done           |++++++++++++++++++++++++++++++++++++++|
config-sha256:1cad2846fc76fdde7217fb06db38fbcdccaed71baccc30a7e8ec70f095ea3d11:   done           |++++++++++++++++++++++++++++++++++++++|
elapsed: 1.1 s                                                                    total:  1.1 Ki (1001.0 B/s)

• I've reviewed the guidance in CONTRIBUTING.md

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[pendo324]

Nice clean change, thanks!