[FLINK-34455] Move RestoreMode from flink-runtime to flink-core

[Zakelly]

What is the purpose of the change

According to the FLIP-406, a new RecoveryOptions class will be introduced in flink-core, which contains options for RestoreMode. Thus the RestoreMode would better be moved to flink-core as well.

Although RestoreMode is @PublicEvolving, there is no public user interface usage of this class (normal user would only use it in configuration), so no breaking change introduced.

Brief change log

• Move RestoreMode to package org.apache.flink.core.execution
• Change all imports of RestoreMode

Verifying this change

This change is a trivial rework and is already covered by existing tests.

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

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)
• The serializers: (yes / no / don't know)
• The runtime per-record code paths (performance sensitive): (yes / no / don't know)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (yes / no / don't know)
• The S3 file system connector: (yes / no / don't know)

Documentation

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

[flinkbot]

CI report:

• 72b5653 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

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

[Zakelly]

@flinkbot run azure

[Zakelly]

@flinkbot run azure

[fredia]

@Zakelly Thanks for the PR, LGTM.

[Zakelly]

@fredia Thanks for your review!