Clean up cat headers

Remove duplicate cache columns, add aliases, normalize header names across actions.

For example:

    ==== nodes ====
    id                       | id,nodeId                 | unique node id
    pid                      | p                         | process id
    host                     | h                         | host name
    ip                       | i                         | ip address
    port                     | po                        | bound transport port
    version                  | v                         | es version
    build                    | b                         | es build hash
    jdk                      | j                         | jdk version
    disk.avail               | d,disk,diskAvail          | available disk space
    heap.percent             | hp,heapPercent            | used heap ratio
    heap.max                 | hm,heapMax                | max configured heap
    ram.percent              | rp,ramPercent             | used machine memory ratio
    ram.max                  | rm,ramMax                 | total machine memory
    load                     | l                         | most recent load avg
    uptime                   | u                         | node uptime
    node.type                | type,dc,nodeType          | d:data node, c:client node
    master                   | m                         | m:master-eligible, *:current master
    name                     | n                         | node name
    completion.size          | cs,completionSize         | size of completion
    fielddata.memory_size    | fm,fielddataMemory        | used fielddata cache
    fielddata.evictions      | fe,fielddataEvictions     | fielddata evictions
    filter_cache.memory_size | fcm,filterCacheMemory     | used filter cache