[hotfix][statebackend/forst] Normalize ForSt option names and working dir

[zoltar9264]

What is the purpose of the change

As title said, normalize ForSt option names and working dir.

Brief change log

• rename option "state.backend.forst.localdir" to "state.backend.forst.local-dir"
• rename option "state.backend.forst.remotedir" to "state.backend.forst.remote-dir"
• fix the forst backend working dir mistake

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)

Please help review this change @masteryhx , thanks.

[flinkbot]

CI report:

• 4f208c4 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[masteryhx]

Thanks for the PR.
PTAL my comments.

[masteryhx]

Thanks for the update.
LGTM.