sqlfmt: add flag version

[JMavs]

Now you can execute sqlfmt -v to know the current version.

[lopezator]

Thank you for your contribution @JMavs !!!

Can we define the version in a const or get the value present in the Makefile somehow? Its 100% likely that I will forget to update the value in two places in the next release and thus, give incorrect data to the user.

[lopezator]

Another question, what happens if we mix the flag --version with sql input (or other flags) passed to sqlfmt?

We should act as the --help does, exiting and doing nothing but the version in that case.

[lopezator]

Another question, what happens if we mix the flag --version with sql input (or other flags) passed to sqlfmt?

We should act as the --help does, exiting and doing nothing but the version in that case.

Example:

> ~$ sqlfmt --len 100 <<< 'select * from users';
SELECT * FROM users

Works.

> ~$ sqlfmt --len 100 --help <<< 'select * from users';
SELECT * FROM users

Exits and prints just the help. --version should do the same.