Validate path types

[rikatz]

What this PR does / why we need it:

Adds validation on the path vs pathType used.
This is a new config on Ingress configmap that is disabled by default (but should be enabled on the next minor version, like v1.8).

When this option is enabled, the path will be validated and the only allowed characters will be "A-Za-z0-9/_-" when the pathType is not ImplementationSpecific.

Cluster admins should validate when users can use ImplementationSpecific, and if there is some dangerous character being used.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• CVE Report (Scanner found CVE and adding report)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

How Has This Been Tested?

Added unit tests on validator, added e2e tests containing valid and invalid scenarios

[k8s-ci-robot]

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[tao12345666333]

/lgtm
/hold

Please cancel the hold, if you wish to.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: rikatz, tao12345666333

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• OWNERS [rikatz,tao12345666333]

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[rikatz]

@strongjz has the final hold cancel

[rikatz]

/hold cancel
Timeout James :P