HONEYCOMB-322: fix hc error after vpp restart if local-mapping was configured

HONEYCOMB-322: fix hc error after vpp restart if local-mapping was configured

In case of honeycomb restart, mapping context is read first.
Then persisted config is being processed.
Therefore customiers should not reject configuration if metadata they are going to
add is already present in mapping context.

Also includes:
* locator-set and remote-mapping handling update
* fixes write order of locator sets and local-mapping.

Not included:
* initializers for lisp (hc restart without vpp restart might fail)

Change-Id: I82c1ee878d9ce074a6bd8197678653814514e6ca
Signed-off-by: Marek Gradzki <[email protected]>