Implemented message passing between FileWatcher and Vert.x

[slinkydeveloper]

Fixes #332

Proposed Changes

• Introduces a bunch of classes to send/receive the contract using the event bus: ContractMessageCodec, ContractPublisher, ResourcesReconcilerMessageHandler
• ConsumerDeployer becomes a verticle that has to be deployed to run. It starts the message consumer and the reconciler internally.
• HttpVerticle in receiver changes a bit its role and becomes ReceiverVerticle. Now, more than being a mere http server starter, it knows about the receiver classes and starts the reconciler message consumer together with the http server. This aligns it with ConsumerDeployer usage and role and also keeps the reconciliation on the same verticle of the listener.
• Renamed RequestReceiver to proper RequestMapper

[codecov]

Codecov Report

Merging #346 into master will increase coverage by 0.22%.
The diff coverage is 75.00%.

@@             Coverage Diff              @@
##             master     #346      +/-   ##
============================================
+ Coverage     76.05%   76.27%   +0.22%     
- Complexity      180      189       +9     
============================================
  Files            49       51       +2     
  Lines          1541     1564      +23     
  Branches         52       53       +1     
============================================
+ Hits           1172     1193      +21     
- Misses          289      291       +2     
  Partials         80       80              

Flag	Coverage Δ	Complexity Δ
#java-unittests	75.43% <75.00%> (+0.46%)	189.00 <23.00> (+9.00)
#unittests	76.27% <75.00%> (+0.22%)	189.00 <23.00> (+9.00)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ	Complexity Δ
...knative/eventing/kafka/broker/dispatcher/Main.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...v/knative/eventing/kafka/broker/receiver/Main.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
...fka/broker/core/eventbus/ContractMessageCodec.java	75.00% <75.00%> (ø)	5.00 <5.00> (?)
...enting/kafka/broker/receiver/ReceiverVerticle.java	92.59% <88.88%> (ø)	3.00 <3.00> (?)
.../kafka/broker/core/eventbus/ContractPublisher.java	100.00% <100.00%> (ø)	3.00 <3.00> (?)
...nciler/impl/ResourcesReconcilerMessageHandler.java	100.00% <100.00%> (ø)	5.00 <5.00> (?)
...ka/broker/dispatcher/ConsumerDeployerVerticle.java	82.22% <100.00%> (ø)	9.00 <3.00> (?)
.../eventing/kafka/broker/receiver/RequestMapper.java	94.59% <100.00%> (ø)	14.00 <4.00> (?)
... and 1 more

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[slinkydeveloper]

flaky not related to this test
/retest

[slinkydeveloper]

@pierDipi sacura error https://prow.knative.dev/view/gs/knative-prow/pr-logs/pull/knative-sandbox_eventing-kafka-broker/346/pull-knative-sandbox-eventing-kafka-broker-integration-tests/1320790707404804096#1:build-log.txt%3A63390

[pierDipi]

/test pull-knative-sandbox-eventing-kafka-broker-integration-tests

[pierDipi]

From the sacura job logs seems like not all events have been sent:

"status_codes": {
   "202": 119951
  },

It should be "202": 120k, so we have been slower to receive and/or consume events.

[pierDipi]

/lgtm

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pierDipi, slinkydeveloper

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