Add version number for hacktv

[Potomac]

Currently hacktv doesn't have version number (no cli option --version or -v), it would be interesting to have this feature,

a scheme like : major.minor[.build[.revision]] (example: 1.2.12.102)

[fsphil]

There is no version number, but I've played about with using a yyyymmdd-commit style version:

$ ./hacktv --version
hacktv 20210116-751e496

Though I'm not completely happy with it.

[alexmyczko]

this is related to https://github.com/fsphil/hacktv/issues/38