Add support for URI remapping

[mre]

Allow users to remap URIs. Regular expressions are supported. Remappings get evaluated in order of definition. Multiple remappings are allowed.
The format is similar to that of markdown-link-check.

How it works ⚙️

Consider the following input:

file://../../issues
https://example.com
https://example.org
https://example.net

Let's remap these inputs using the --remap parameter:

lychee --remap 'https://example.com http://127.0.0.1:8080' \
       --remap 'https://example.org https://staging.example.com' \
       --remap '../../issues https://github.com/usnistgov/OSCAL/issues' \
       -- input.md

This would check the following URIs:

https://github.com/usnistgov/OSCAL/issues
http://127.0.0.1:8080/
https://staging.example.com/
https://example.net/

Caveats 🚩

• Be careful when using this feature because checking every link against a large set of regular expressions has a performance impact even though the Rust regex engine is very fast.
• There are no constraints on the URI mapping, so the rules might contradict each other. It's the user's responsibility to make sure this does not happen.
• File remappings might be a bit surprising. Files are handled as URIs internally and get prefixed with a file:// scheme. As a consequence, using ^../../issues as a remap pattern would never match. Instead ../../issues (without the ^) would work.

Open Questions 🤔 (please provide feedback)

• Shall we first remap a URI and then check if it is excluded or vice versa? 🤔

Fixes #547

[mre]

Any comments before this gets merged?