feat: match patterns in ssh_aliases

[legobeat]

Describe what this PR does / why we need it

Some people may use "dynamic" remote hosts like github.com-foo, github.com-bar, etc. Having to additionally add each as an explicit ssh_aliases entry can become a chore.

Does this pull request fix one issue?

Describe how you did it

Interpret keys in ssh_alieses configuration as Lua patterns. This allows an alias like github\.com-.*.

Describe how to verify it

Special notes for reviews

Checklist

• Passing tests and linting standards
• Documentation updates in README.md and doc/octo.txt

[btkramm]

This pull request created a bug when using ssh_aliases!

The issue is with the pattern in the gsub call. When you use "^" .. alias .. "$", Lua treats special characters in alias literally, but you need to escape them to match them literally in the pattern.

The following ssh_aliases configuration does not work:

    ssh_aliases = {
      ['github.com-personal'] = 'github.com',
      ['github.com-work'] = 'github.com',
    },

and the following, does:

    ssh_aliases = {
      ['github.com%-personal'] = 'github.com',
      ['github.com%-work'] = 'github.com',
    },

In my case, github.com-work contains a hyphen (-) which has special meaning in Lua pattern, and the gsub call is unable to replace the host.