fix http / grpc route rule generation

[zac-nixon]

Description

When no matches are given to for a HTTP / GRPC Route Rule, the controller doesn't generate any ALB rules. This behavior is incorrect as per the Gateway API documentation:

For GRPC routes -

	// If no matches are specified, the implementation MUST match every gRPC request.

For HTTP routes -

	// If no matches are specified, the default is a prefix
	// path match on "/", which has the effect of matching every
	// HTTP request.

This PR implements the logic as specified ^^^. I also added unit tests to validate the change worked. I was able to validate my GRPC set up now works with this change.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

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This pull-request has been approved by: zac-nixon

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[shuqz]

i think getHttpMatchPrecedenceInfo(&httpMatch, &match) is missing when route does not match. it is ok for most of them (headers/query params) because if those does not get specified,they will have default value 0 or false. but at least for pathType, we want to treat them like prefix /*

func getHttpMatchPrecedenceInfo(httpMatch *v1.HTTPRouteMatch, matchPrecedence *RulePrecedence) {
	matchPrecedence.HttpSpecificRulePrecedenceFactor.PathType = getHttpRoutePathType(httpMatch.Path)
	// httpMatch.Path.Value won't be nil, default is /
	matchPrecedence.HttpSpecificRulePrecedenceFactor.PathLength = len(*httpMatch.Path.Value)
	matchPrecedence.HttpSpecificRulePrecedenceFactor.HasMethod = httpMatch.Method != nil
	matchPrecedence.HttpSpecificRulePrecedenceFactor.HeaderCount = len(httpMatch.Headers)
	matchPrecedence.HttpSpecificRulePrecedenceFactor.QueryParamCount = len(httpMatch.QueryParams)

}

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