Update GitHub Action for BCR Reviewer (#1912)

- Merged the module maintainer notifier and the PR approval into one
  action, which can be distinguished by the "action-type" input.
- Implement a new functionality to dismiss stale approvals from all
reviewers.
The default `Dismiss stale pull request approvals when new commits are
pushed` option from GitHub doesn't dismiss approvals from users who is
not a repo maintainer. This helps address the concern that a local
commit was made before the approval but pushed after it. See
https://github.com/bazelbuild/bazel-central-registry/pull/1549#discussion_r1506081777
1063 files changed