Added initial implementations of to<T> functions

[jmacgowan]

• Added to<> function for: presentation, knuth_bendix, froidure_pin, congruence.
• Added tests for all
• NOTE: This PR does not extend any of the unimplemented templates that exist in libsemigroups, such as the stdstring option for presentations, however it covers all 10 FroidurePin instantiations that already existed.

@james-d-mitchell

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (main@aa76229). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #99   +/-   ##
=======================================
  Coverage        ?   73.69%           
=======================================
  Files           ?       26           
  Lines           ?     1574           
  Branches        ?        0           
=======================================
  Hits            ?     1160           
  Misses          ?      414           
  Partials        ?        0           

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jswent]

Hi @jmacgowan, sorry I missed this. I will have a look at it tonight.

In the future, feel free to ping me if you want to get my attention, as I get a lot of activity on GitHub so stuff gets buried.

EDIT: Unless @james-d-mitchell would you prefer to review this?