MULE-7524: Encoded characters not working when using expressions for dyn...

...amic endpoints

_ Adding property getters in URIBuilder
_ Creating DynamicURIBuilder to create dynamic endpoint's URIs
_ Updating DynamicOutboundEndpoint to use a DynamicURIBuilder
_ Updating DynamicOutboundEndpoint creation on HttpProxy
_ Updating old tests that were using encoded mule expressions in the address's path
_ Updating migration guide