Improve ingress component-route update and removal UX

Summary

Follow up on the component-route UX introduced in #3403. Evaluate a clearer, explicit interface for updating and removing individual ingress component routes.

Current behavior and problem

rosa edit ingress --component-routes supports partial updates: routes omitted from an invocation remain unchanged. Removing a route currently relies on supplying the existing DSL with empty values, for example:

rosa edit ingress -c <cluster> \
  --component-routes 'downloads: hostname=;tlsSecretRef=' <ingress-id>

This is difficult to discover, requires users to know the internal route fields, and can be easy to mistype or misquote because the DSL uses semicolons.

Requested evaluation

1. Evaluate an explicit removal option, for example:

   rosa edit ingress <ingress-id> -c <cluster> \
     --remove-component-route downloads
   

2. Evaluate more standard component-route update representations, such as:

   • repeatable key-value input, for example --component-route name=console,hostname=console.example.com,tlsSecretRef=console-tls;
   • a JSON or YAML payload alternative, if consistent with existing ROSA CLI conventions.

The final interface should preserve the distinction between:

• omitting a route: leave it unchanged;
• updating a route: set the supplied values;
• removing a route: explicit deletion/clear operation.

Affected areas

• rosa edit ingress command and its flag parsing under cmd/edit/ingress
• CLI help text and parser/request tests
• Any applicable ingress E2E coverage or documentation

Acceptance criteria

• The removal flow is explicit and documented; it does not require users to provide empty hostname and tlsSecretRef values.
• Partial update semantics remain unchanged: routes not named by update or removal options are preserved.
• The chosen update input format is evaluated for consistency, discoverability, shell safety, validation, and backward compatibility.
• Unit/request tests cover updating one route, removing one route while preserving another, invalid route names, and duplicate/conflicting input.
• CLI help documents update versus removal behavior and examples.

References

• Originating pull request: https://github.com/openshift/rosa/pull/3403
• Originating discussion: https://github.com/openshift/rosa/pull/3403#issuecomment-5035316369
• Requested by: @amandahla