Support cors-allow-origin with multiple origins (#7614)

* Add Initial support for multiple cors origins in nginx

- bump cluster version for `make dev-env`
- add buildOriginRegex function in nginx.tmpl
- add e2e 4 e2e tests for cors.go
- refers to feature request #5496

* add tests + use search to identify '*' origin

* add tests + use search to identify '*' origin

Signed-off-by: Christopher Larivière <lariviere.c@gmail.com>

* fix "should enable cors test" looking at improper values

* Modify tests and add some logic for origin validation

- add origin validation in cors ingress annotations
- add extra tests to validate regex
- properly escape regex using "QuoteMeta"
- fix some copy/paste errors

* add TrimSpace and length validation before adding a new origin

* modify documentation for cors and remove dangling comment

* add support for optional port mapping on origin

* support single-level wildcard subdomains + tests

* Remove automatic `*` fonctionality from incorrect origins

- use []string instead of basic string to avoid reparsing in template.go
- fix typo in docs
- modify template to properly enable only if the whole block is enabled
- modify cors parsing
- test properly by validating that the value returned is the proper
  origin
- update unit tests and annotation tests

* Re-add `*` when no cors origins are supplied + fix tests

- fix e2e tests to allow for `*`
- re-add `*` to cors parsing if trimmed cors-allow-origin is empty
(supplied but empty) and if it wasn't supplied at all.

* remove unecessary logic for building cors origin + remove comments

- add some edge cases in e2e tests
- rework logic for building cors origin

there was no need for logic in template.go for buildCorsOriginRegex
if there is a `*` it ill be short-circuited by first if.

if it's a wildcard domain or any domain (without a wildcard), it MUST
match the main/cors.go regex format.

if there's a star in a wildcard domain, it must be replaced with
`[A-Za-z0-9]+`

* add missing check in e2e tests

go.mod

@@ -78,6 +78,7 @@ require (
 	github.com/go-openapi/jsonreference v0.19.3 // indirect
 	github.com/go-openapi/spec v0.19.5 // indirect
 	github.com/go-openapi/swag v0.19.5 // indirect
+	github.com/go-task/slim-sprig v0.0.0-20210107165309-348f09dbbbc0 // indirect
 	github.com/godbus/dbus/v5 v5.0.4 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect