Optimize API calls

[dsame]

Description:

Each next run should not proceed the issues proceed during the previous run. In the other case running from the very beginning never reach the issues beyond API limit.

Changes:

1. removed unnecessary extra call to getPullRequest API, this implied adding isDraft property and refactoring unit tests
2. Introduced and implemented IState interface with persist, rehydrate and reset method

• rehydrate is called before the processing
• persist is called after the processing
• reset when all the issues are processed and the next run should be started from the beginning

1. Every issue is marked as processed with IState.isIssueProcessed method and it is skipped during the processing if IState.isIssueProcessed returns true for it

Implementation details:

• getStateInstance introduced for mocking during testing
• persistence implemented with @actions/http-client (to store state) and octokit (to remove state)

Related issue:
link to the related issue.

Check list:

• Mark if documentation changes are required.
• Mark if tests were added or updated to cover the changes.

[dusan-trickovic]

Everything looks alright to me :) Tested a workflow run using this branch and everything works error-free. The comments I left below are just nitpicks and can be ignored, as there are no problems present. Thank you!

[msorens]

Typos in the readme:
s/proceeded/processed/g