refactoring(events-bus): events bus refactoring

[rustatian]

Reason for This PR

• closes: https://github.com/spiral/roadrunner/issues/496

Description of Changes

• Update all instances of the old events.Handler.
• Expose kv, jobs, broadcast interfaces via rr-plugins API. (rr-plugins/api).

License Acceptance

By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.

PR Checklist

[Author TODO: Meet these criteria.] [Reviewer TODO: Verify that these criteria are met. Request changes if not]

• [x] All commits in this PR are signed (git commit -s).
• [x] The reason for this PR is clearly provided (issue no. or explanation).
• [x] The description of changes is clear and encompassing.
• [x] Any required documentation changes (code and docs) are included in this PR.
• [x] Any user-facing changes are mentioned in CHANGELOG.md.
• [x] All added/changed functionality is tested.

[codecov[bot]]

Codecov Report

Merging #103 (a896ffb) into master (b483288) will decrease coverage by 2.47%. The diff coverage is 83.76%.

@@            Coverage Diff             @@
##           master     #103      +/-   ##
==========================================
- Coverage   67.78%   65.31%   -2.48%     
==========================================
  Files         129      134       +5     
  Lines       10437    10780     +343     
==========================================
- Hits         7075     7041      -34     
- Misses       2668     3034     +366     
- Partials      694      705      +11     

Impacted Files	Coverage Δ
amqp/amqpjobs/item.go	73.28% <ø> (ø)
api/proto/jobs/v1beta/jobs.pb.go	36.26% <ø> (ø)
api/proto/kv/v1beta/kv.pb.go	42.76% <ø> (ø)
api/proto/websockets/v1beta/websockets.pb.go	49.65% <ø> (ø)
api/pubsub/psmessage.go	0.00% <ø> (ø)
boltdb/boltkv/driver.go	51.69% <ø> (ø)
informer/plugin.go	71.05% <0.00%> (ø)
informer/rpc.go	64.00% <0.00%> (ø)
jobs/protocol/error.go	47.82% <ø> (ø)
jobs/protocol/protocol.go	73.13% <ø> (ø)
... and 54 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update b483288...a896ffb. Read the comment docs.