Get command

[marc-48k]

#302 adds the ability to retrieve individual configuration items via the get command.

Examples:

Help

$tart get monterey-base --help 
OVERVIEW: Get a VM's configuration

USAGE: tart get <name> [--cpu] [--memory] [--disk-size] [--display]

ARGUMENTS:
  <name>                  VM name.

OPTIONS:
  --cpu                   Number of VM CPUs.
  --memory              VM memory size in megabytes.
  --disk-size             Disk size in gigabytes.
  --display               VM display resolution in a format of
                          <width>x<height>. For example, 1200x800.
  --version               Show the version.
  -h, --help              Show help information.

Get CPU

$tart get monterey-base --cpu 
4

Error - Get 2 things

$tart get monterey-base --cpu --disk-size
Error: Options --cpu, --memory, --disk-size and --display are mutually exclusive
Usage: tart get <name> [--cpu] [--memory] [--disk-size] [--display]
  See 'tart get --help' for more information.

[fkorotkov]

Could you please rebase after some refactorings in #352?