[hbck2] Queue an assign of hbase:meta and bulk assign/unassign

Adds 'raw' assigns/unassigns to the Hbck Service. Takes a list of encoded region names and bulk assigns/unassigns. Skirts Master 'state' check and does not invoke Coprocessors. For repair only. Here is what HBCK2 usage looks like now: {code} $ java -cp hbase-hbck2-1.0.0-SNAPSHOT.jar org.apache.hbase.HBCK2 usage: HBCK2 <OPTIONS> COMMAND [<ARGS>] Options:  -d,--debug run with debug output  -h,--help output this help message     --hbase.zookeeper.peerport peerport of target hbase ensemble     --hbase.zookeeper.quorum ensemble of target hbase     --zookeeper.znode.parent parent znode of target hbase Commands:  setTableState <TABLENAME> <STATE>    Possible table states: ENABLED, DISABLED, DISABLING, ENABLING    To read current table state, in the hbase shell run:      hbase> get 'hbase:meta', '<TABLENAME>', 'table:state'    A value of \x08\x00 == ENABLED, \x08\x01 == DISABLED, etc.    An example making table name 'user' ENABLED:      $ HBCK2 setTableState users ENABLED    Returns whatever the previous table state was.  assign <ENCODED_REGIONNAME> ...    A 'raw' assign that can be used even during Master initialization.    Skirts Coprocessors. Pass one or more encoded RegionNames:    e.g. 1588230740 is hard-coded encoding for hbase:meta region and    de00010733901a05f5a2a3a382e27dd4 is an example of what a random    user-space encoded Region name looks like. For example:      $ HBCK2 assign 1588230740 de00010733901a05f5a2a3a382e27dd4    Returns the pid of the created AssignProcedure or -1 if none.  unassign <ENCODED_REGIONNAME> ...    A 'raw' unassign that can be used even during Master initialization.    Skirts Coprocessors. Pass one or more encoded RegionNames:    Skirts Coprocessors. Pass one or more encoded RegionNames:    de00010733901a05f5a2a3a382e27dd4 is an example of what a random    user-space encoded Region name looks like. For example:      $ HBCK2 unassign 1588230740 de00010733901a05f5a2a3a382e27dd4    Returns the pid of the created UnassignProcedure or -1 if none. {code}