feat(results): Add boot subcommand

[CamilaAlvarez]

Add a boot subcommand to results.

Now we can both obtain all boots per tree and a single boot by id, just like with tests and builds.

The subcommand supports the same arguments as results testand results build.
An example of usage would be:

kci-dev results boot --id 'maestro:67ffde3a69241b2ece0ccaa6' 

[padovan]

Thank you!

[aliceinwire]

thanks!