Create a factory service that can create GeoIp2\Database\Reader instances at runtime

[acelaya]

Closes #59

Part of shlinkio/shlink#2021

This PR stops using and registering GeoIp2\Database\Reader as a singleton service, and instead provides a new factory service which creates Reader instances at runtime.

This is needed because GeoIp2\Database\Reader instances are stateful, and they hold a reference to the metadata of the first file they were created with.

The new service will ensure every time an interaction with the GeoLite2 file is needed, it will be done with an up-to-date copy.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.92%. Comparing base (0035a72) to head (b085cc5).
Report is 2 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main      #60      +/-   ##
============================================
+ Coverage     98.87%   98.92%   +0.04%     
- Complexity       33       35       +2     
============================================
  Files            10       11       +1     
  Lines            89       93       +4     
============================================
+ Hits             88       92       +4     
  Misses            1        1              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.