Add a GitHub Action to get all contracts

[turbolent]

Description

Add a separate GitHub Action that allows getting all contracts for a chain, extracted from the existing backward compatibility checking action, i.e. re-using the get-contracts tool.

Also, include the contracts in the backward compatibility checking actions' artifacts.

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• [x] Targeted PR against master branch
• [x] Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• [x] Code follows the standards mentioned here
• [x] Updated relevant documentation
• [x] Re-reviewed Files changed in the Github PR explorer
• [x] Added appropriate labels

[github-actions[bot]]

Cadence Benchstat comparison

This branch with compared with the base branch onflow:master commit 1b27cc33d957d6f8af89c93c4cc76e1be66c8f5f The command for i in {1..N}; do go test ./... -run=XXX -bench=. -benchmem -shuffle=on; done was used. Bench tests were run a total of 7 times on each branch.

Collapsed results for better readability