Added support for /modules, /modules/module, /operations resources

support for:
/restconf/modules
/restconf/modules/pathToMountPoint/yang-ext:mount
/restconf/modules/module/moduleName/revision
/restconf/modules/module/pathToMountPoint/yang-ext:mount/moduleName/revision
/restconf/operations
/restconf/operations/pathToMountPoint/yang-ext:mount

revision must be in format "yyyy-MM-dd"

test for URIs:
- /modules
- /modules/module/<module_name>/<module_revision>
- /operations
- /modules/......./yang-ext:mount
- /modules/module/........../yang-ext:mount/<module_name>/<module_revision>
- /operations/........../yang-ext:mount

Change-Id: I7169a25024598dd3b49d7960d1ef90bc40c5d1d5
Signed-off-by: Martin Sunal <msunal@cisco.com>
Signed-off-by: Jozef Gloncak <jgloncak@cisco.com>
Merge "Added support for /modules, /modules/module, /operations resources"