Limited MRT ingress unit

[DRiKE]

Mainly for testing purposes (though eventually probably interesting for e.g. researchers), we want a unit to ingress MRT files. Focus is limited to:

• [ ] rib dumps, i.e. TableDumpV2 types
• [ ] unicast v4+v6

Nice to haves:

• [ ] HTTP endpoint to trigger processing of new files
• [ ] info via the HTTP api: which files have been processed, which file is currently being processed, other stats