[FLINK-7711] Port JarListHandler to WebMonitorEndpoint

[FangYongs]

What is the purpose of the change

Port JarListHandler to WebMonitorEndpoint

Brief change log

• Create JarWithProgramUtils from PackageProgram to check jar file
• Create new JarListHandler and JarListInfo
• Add uploadDir to RestHandlerConfiguration

Verifying this change

This change added tests and can be verified as follows:

• Added test case JarListInfoTest

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, 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 / docs / JavaDocs / not documented)

[GJL]

Thank you for your contribution to Flink @zjureel! I left a comment about the duplicated code from PackagedProgram. Also I think that we should implement and merge FLINK-7713 first so that we are able verify the functionality end-to-end. Let me know what you think.

[GJL]

I can see that you had to copy a lot of code from PackagedProgram because flink-runtime does not have a dependency on flink-clients. Also, JobWithJars had to be moved to the flink-runtime module. I think we should try to avoid duplicating the code in PackagedProgram.

After talking to @tillrohrmann offline, we think that we could achieve this by putting the new JarUploadHandler into the flink-runtime-web module. This module already has a dependency to flink-clients and flink-runtime. In WebMonitorEndpoint, the jar handlers could be dynamically loaded according to whether flink-runtime-web is in the classpath or not; similar to the StaticFileServerHandler (see WebMonitorUtils.tryLoadWebContent()).

What do you think?