[Form] Avoid Utils.getURL(), instead use Linkchecker/ResourceResolverMapTransformer/...

When rendering the form container component, when determining the form action, the following method is called:
`this.action = Utils.getURL(request, currentPage);`
https://github.com/Adobe-Marketing-Cloud/aem-core-wcm-components/blob/d4a9c2c7785f5d50e91dd2ebe145ace4a0bb7491/bundles/core/src/main/java/com/adobe/cq/wcm/core/components/internal/models/v1/form/ContainerImpl.java#L123

I am not happy with this approach:
1. In case the user enters "test" as a sling:vanityUrl, this value will be used literally; Meaning the tag will be `` which will of course go wrong (there is probably a lot more logic involved, than just taking the value and putting it in an HTML attribute)
2. The form container component (and other components) should not have the responsibility of rendering these mapped/transformed urls, but instead the responsibility should be within the frameworks we already have available (linkchecker, resourceresolvermaptransformer in acs commons, resourceResolver.map() which takes sling:vanityUrls into account)

https://cwiki.apache.org/confluence/display/SLING/Flexible+Resource+Resolution#FlexibleResourceResolution-CurrentStatus

Start in bundles/core/src/main/java/com/adobe/cq/wcm/core/components/internal/models/v1/form/ContainerImpl.java around line 123 and review how the form action is obtained. Read the linked Sling flexible resource resolution guidance and compare the available Linkchecker, ResourceResolverMapTransformer, and resourceResolver.map() approaches. Done means the form container no longer directly relies on Utils.getURL and handles vanity URLs through the chosen framework mechanism.

Written by the indexing model from the issue text.