Add Support for Priority Configuration in HTTPRoute Resource

[rlymbur]

What type of PR is this?

Feature

Which issue does this PR fix:

#719

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

This adds support for a custom annotation on HTTPRoutes to manually assign a priority for a rule. You can manually assign priorities to rules using the custom annotation application-networking.k8s.aws/rule-{index}-priority.

Testing done on this change:

Automation added to e2e:

test/suites/integration/httproute_rule_priority_test.go was added to confirm manually assigned priorities are reflected on VPC Lattice resources correctly.

Will this PR introduce any new dependencies?:

No.

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

No, this change is backwards compatible with existing routes.

Does this PR introduce any user-facing change?:

Added support for priority configuration in HTTPRoute resource

Do all end-to-end tests successfully pass when running make e2e-test?:

------------------------------

Ran 57 of 70 Specs in 3137.264 seconds
SUCCESS! -- 57 Passed | 0 Failed | 0 Pending | 13 Skipped
--- PASS: TestIntegration (3137.27s)
PASS
ok      github.com/aws/aws-application-networking-k8s/test/suites/integration   3137.863s

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