RFE: Support alias names for checks instead of only numeric ids

[tyll]

For bugs

For new checks and feature suggestions

• [N/A] shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

# shellcheck disable=expansion-in-single-quotes
xx='$i_dont_want_to_expand_the_var_here'

Here's what shellcheck currently says:

It only supports codes like SC2016

Here's what I wanted or expected to see:

Being able to specify names instead of codes to make it easier to understand which code is ignored.