[7.x] Add category field to deprecation logs

[pgomulka]

Deprecation logs in 7.x are using ESJsonLayout and it requires
additional fields to be declared in a log4j config in order to emit
values to logs.
This commit adds category field to deprecation log pattern

context: in 8.0 we use ECSLayout which do not require to declare additional fields upfront. In 7.x we have to declare them in the logging config. The PR introducing categories in master #67443. A backport to 7.x which missed this field #68061

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[pgomulka]

ok to test

[pgomulka]

@elasticmachine test this please

[pgomulka]

@elasticmachine update branch

[elasticmachine]

merge conflict between base and head

[grcevski]

LGTM! This looks good to me, I just had a question for my own better understanding, does the order of the fields declared in the .properties files matter? I can see that DeprecationIndexingComponent sets them in this order category,key,x-opaque-id, which is reversed from the properties files.

[ChrisHegarty]

LGTM.

[pgomulka]

I just had a question for my own better understanding, does the order of the fields declared in the .properties files matter? I can see that DeprecationIndexingComponent sets them in this order category,key,x-opaque-id, which is reversed from the properties files.

@grcevski good catch! To be fair it would be better if we have them in the same order, but at the same time I don't think this would affect anyone - it is just the order of fields in indexed JSON vs order of fields in a log.
The order on other fields is also mixed.
I guess we could follow up with a separate cleanup PR for this.