Eliminate JaxRsApiPath

Eliminate JaxRsApiPath

Bouncing through JaxRsApiPath is not entirely optimal, as we need to
expose that class -- which really is an implementation detail.

Eliminate the class in favor of JaxRsRestconf implementing
ParamConverterProvider for ApiPath.

While we could provide this support as an external component, inlining
it in JaxRsRestconf, which is the only relevant user, has the added
benefit of suppressing Jersey warnings about the resource not providing
any provider interfaces.

JIRA: NETCONF-1157
Change-Id: Id3d1cc5acf764bc03a46f792b3d8c2bf72c5bd85
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>