Deprecate async replication

[dadoonet]

Follow up for PR #10171.

As we discussed #10114 (comment), we should also mark the code as deprecated so plugin developers know in advance that they need to adapt their code.

I also added a log when using replication parameter in REST APIs but as info Level. I wonder if I should better log that as a WARN if debug level is set? So people in debug mode will see this information as a WARN while it won't pollute logs for each call when in default INFO log level.

[javanna]

Thanks for openinig this @dadoonet , it LGTM. As for deprecation warnings, I think they should be warn, but let's hear what @clintongormley thinks. It would be great to have all of the deprecation logs from the same logger, so that they can all be enabled at once when needed, but this might require some more work and overlap with other work in progress that I'm not sure about.

[dadoonet]

Ah! So we could create a DeprecationLogger class and allow a global activation or not. Would be super nice indeed!

[jpountz]

@dadoonet @javanna I think we should remove deprecation warnings from this PR and instead make sure that the replication type is parsed with ParseField so that we have a single entry point if we want to log about usage of deprecated APIs.

[clintongormley]

I think the deprecation message should be a warning, and I agree with #10642 (comment) (see #8963)

[clintongormley]

@dadoonet any movement here?

[dadoonet]

@clintongormley I was wondering if I should wait for #11033 to be merged in so I can update the deprecation notice there?

[jpountz]

Hmm, actually ParsedField might not be applicable here (or in an awkward way) since we do not perform parsing, however I think this PR should use #11033 once it's in.

[s1monw]

@dadoonet can you move this forward if possible?

[dadoonet]

@s1monw Thanks for the heads up. Now that #11285 has been merged, I'm going to update the PR and use the deprecation logger. Stay tuned! :)

[dadoonet]

Actually, the deprecation logger has been merged only in master (2.0) but is not available in 1.x.
The plan is to deprecate in docs in 1.x and use the deprecation logger in master.

[javanna]

maybe add also what the method does, although quite self-explaining

[javanna]

LGTM besides the tiny javadoc comment I left

[dadoonet]

merged in 1.x with 1493cfb