Refactor event handling and remove service reconciler

[solmonk]

What type of PR is this?

refactoring/enhancement

Which issue does this PR fix:

#359

What does this PR do / Why do we need it:

We have multiple reconcilers that do the same thing which causes bug #359, and it is really hard to understand what is going on event handler. I did a refactoring to help clarify which resource events are mapped to which other resources.

• (Almost) deleted service reconciler, now it only removes finalizer for keeping compatibility. Its main purpose was watching endpoint event, so now it is watched on serviceexport / route reconcilers instead.
• Removed and unified event handlers. Now service event handler covers all service related events such as policy and endpoints.
• Added mapper.go under event handler package dedicated to resource mapping using k8s client api calls
• Added a few unit tests on event handler

If an issue # is not available please add repro steps and logs from aws-gateway-controller showing the issue:

Testing done on this change:
e2etest, also manually tested #359 case by updating existing service endpoints.

Automation added to e2e:

Will this PR introduce any new dependencies?:

Will this break upgrades or downgrades. Has updating a running cluster been tested?:

Does this PR introduce any user-facing change?:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[coveralls]

Pull Request Test Coverage Report for Build 5993051159

• 131 of 183 (71.58%) changed or added relevant lines in 5 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+1.7%) to 39.191%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
controllers/serviceexport_controller.go	0	3	0.0%
controllers/eventhandlers/serviceimport.go	14	18	77.78%
controllers/eventhandlers/service.go	34	41	82.93%
controllers/route_controller.go	0	8	0.0%
controllers/eventhandlers/mapper.go	83	113	73.45%

Files with Coverage Reduction	New Missed Lines	%
controllers/service_controller.go	1	0.0%
controllers/eventhandlers/service.go	2	81.25%

Totals
Change from base Build 5992865652:	1.7%
Covered Lines:	4003
Relevant Lines:	10214

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 5993051159

• 131 of 183 (71.58%) changed or added relevant lines in 5 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+1.7%) to 39.191%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
controllers/serviceexport_controller.go	0	3	0.0%
controllers/eventhandlers/serviceimport.go	14	18	77.78%
controllers/eventhandlers/service.go	34	41	82.93%
controllers/route_controller.go	0	8	0.0%
controllers/eventhandlers/mapper.go	83	113	73.45%

Files with Coverage Reduction	New Missed Lines	%
controllers/service_controller.go	1	0.0%
controllers/eventhandlers/service.go	2	81.25%

Totals
Change from base Build 5992865652:	1.7%
Covered Lines:	4003
Relevant Lines:	10214

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 5993051159

• 131 of 183 (71.58%) changed or added relevant lines in 5 files are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+1.7%) to 39.191%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
controllers/serviceexport_controller.go	0	3	0.0%
controllers/eventhandlers/serviceimport.go	14	18	77.78%
controllers/eventhandlers/service.go	34	41	82.93%
controllers/route_controller.go	0	8	0.0%
controllers/eventhandlers/mapper.go	83	113	73.45%

Files with Coverage Reduction	New Missed Lines	%
controllers/service_controller.go	1	0.0%
controllers/eventhandlers/service.go	2	81.25%

Totals
Change from base Build 5992865652:	1.7%
Covered Lines:	4003
Relevant Lines:	10214

---

💛 - Coveralls