feat: build-workspace-matrix supports Echo flag

[amartin-isp]

Adding support to build-workspace-matrix for flags in the dependency glob expression. The flags are meant to modify the behavior of the tool and or its output.

This PR introduces the Echo flag which is meant to cause the tool to simply return the workspace in the dependency glob expression as configured without attempting to minMatch it against existing workspaces.

One use-case for this feature is for automating terraform plan accross multiple repositories. For example, the con-eng-infra repo hosts the stream-cluster module. When the module is updated, a Github action will checkout the kubernetes_management repo and run a terraform plan for every stream-cluster-* root module in the repo.

E.g:

jobs:
  determine-matrix:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.build-workspace-matrix.outputs.matrix }}
    steps:
      - uses: actions/checkout@v4
      - id: build-workspace-matrix
        uses: iStreamPlanet/github-actions/[email protected]
        with:
          github-token: ${{secrets.GITHUB_TOKEN}}
          workspaces: |
            clusters/aws/us-east-1/stream-prod-use1-c/ : modules/stream-cluster/* | Echo
            clusters/aws/us-east-1/stream-prod-use1-d/ : modules/stream-cluster/* | Echo
            clusters/aws/us-east-1/stream-stage-use1-b/ : modules/stream-cluster/* | Echo
            clusters/aws/us-west-2/stream-prod-usw2-c/ : modules/stream-cluster/* | Echo
            clusters/aws/us-west-2/stream-prod-usw2-d/ : modules/stream-cluster/* | Echo
            clusters/aws/us-west-2/stream-stage-usw2-b/ : modules/stream-cluster/* | Echo