[FLINK-8475][config][docs] Integrate more ConfigOptions into documentation

[zentol]

What is the purpose of the change

This PR significantly extends the integration of ConfigOptions into the configuration documentation. The only sections left to integrate are High-availability, ResourceManager and core options.

Each section was integrated in it's own commit that is essentially self-contained.

Most commits are straight-forward and revolve around setting up the description via ConfigOption#withDescription, generating the table and including it in config.md.

Some commits also include migration of existing ConfigConstants to ConfigOptions, but overall very few changes were made.

This PR also includes a minor modification to the generated tables which renames the "Default Value" column to "Default" to save some space.

Verifying this change

The documentation changes can be verified by building the docs locally as described in in flink/docs/README.md.

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): (yes)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable)

[zentol]

Will split this PR into smaller chunks to make it easier to review.