feat: add natural language de/serialization as a companion package

[paviad]

Adds natural language serialization and deserialization of recurrence patterns as a separate library.

Closes #576

[paviad]

I just want to give credit where credit is due, the source code here is a manual porting of the code in the Typescript's library from https://github.com/jakubroztocil/rrule

The ported part is the source in the nlp folder at https://github.com/jakubroztocil/rrule/tree/master/src/nlp

[paviad]

I do not understand these test failures, how do I resolve them?

[axunonb]

When clicking the link 42 Security Hotspots you'll see the solution. It's about a missing timeout for Regex expressions, which is a risk for DoS attacks. Please also have a look at this announcement.

[sonarcloud[bot]]

Quality Gate passed

Issues
38 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud