Fix warnings lucode2::buildLibrary()

[ahagen-pik]

Purpose of this PR

Fixes all 270 'no visible binding' NOTES of lucode2::buildLibrary() from R CMD Check which come from NSE in the data.table package as well as missing function import.

Checklist:

• I used ./test-standard-runs to compare and archive the changes introduced by this PR in /p/projects/edget/PRchangeLog/
• I additionally checked that iterativeEDGETransport works without problem, REMIND is running for >15 iterations

Further information (optional):

• Test runs are here: /p/projects/edget/PRchangeLog/20241212_fixWarningsEDGET
• Comparison of results (what changes by this PR?): Nothing on the functionality/simulation results, but lucode2::buildLibrary() is clean again.

[fbenke-pik]

Great, thanks!

[jmuessel]

Wow, great job!