Improve string field rendering

[sam-f0]

The current representation of string field is as follows:

 Token Descriptor: string
      Length: 36
      Value: android.os.INetworkManagementService

When showing string arrays etc. this is a very verbose output format. It would be better to specialise the output from string fields so its rendered something like:

Token Descriptor: string (36) "Value: android.os.INetworkManagementService"

The hexdump view also supports showing multiple selections at once so this ticket should cover highlighting the size and string content separately.