Remove hawkular/middleware code

[himdel]

Hawkular support was removed long ago, but we still have code referencing it.

@skateman started by removing all the middleware files, (#3897)

but we still have 105 hawkular mentions in the UI code, and 192 middleware mentions.
(Some of which are js middleware, but not a lot.)

Related to:

• Remove middleware/hawkular code manageiq#19361
• Missing migrations for hawkular removal manageiq-schema#423

EDIT: for clarity - only middleware hawkular is being removed. Hawkular is also a valid openshift container metrics setting, that's staying

[himdel]

more progress in #6548

[himdel]

Remaining files with middleware:

$ find | grep middleware | grep -v node_modules | grep -v miq-redux
./spec/javascripts/fixtures/json/toolbar_middleware_server_detail.json
./spec/javascripts/fixtures/json/toolbar_middleware_server_list.json

remaining files with hawkular - none, hawkular_proxy_service.rb is kubernetes metrics capture and thus still used.

We still have 97 hawkular occurences in code, and about 113 middleware refences (skipping miq-redux code, which refers to different middleware).