Add aliases to the client cache daemon and make them searchable

[talanknight]

Sample output with an alias synced to the client cache:

> boundary daemon status

Status:
  Domain Socket:       /Users/myuser/.boundary/socket/daemon.sock
  Log Location:        /Users/myuser/.boundary/cache.log
  Uptime:              9s
  User Count:          1
  Version:             Boundary v0.15.0 (5e5351c359eda7405092684751e1d5661d83e1c6+CHANGES)

  User:
    Address:                        http://127.0.0.1:9200
    AuthToken Count:                1
    Id:                             u_PiGanDGtWI
    Search Support:                 Supported
    Since Search Support Check:     8s
    AuthToken:
      Id:                      at_Qdn6lc6Cj9
      In Keyring:              true
    Alias:
      Count:                     1
      Since Initial Fetch:       8s
      Since Last Refresh:        8s
    Target:
      Count:                     2
      Since Initial Fetch:       8s
      Since Last Refresh:        8s
    Session:
      Count:                   0

> boundary search -resource aliases -query 'value%"example"'

Alias information:
  ID:                    alt_5zXr5Fvs0w
    Scope ID:            global
    Version:             1
    Type:                target
    DestinationId:       ttcp_yWzWYiuOzl
    Value:               example.boundary
    Authorized Actions:
      delete
      no-op
      read
      update