Draft PR for review of the Templates package

[AntoineGautier]

For review only: this shall not be merged.

This branch has a dependency to issue1913_g36_final and therefore cannot be merged before issue1913_g36_final is merged (and pending comments at https://github.com/lbl-srg/modelica-buildings/issues/1913#issuecomment-1021172412 and below are adressed).

The classes of interest for the review are within Buildings.Templates. Please review as it was intended to be merged to MBL master. Only the above dependency still prevents from merging but the package should otherwise be ready for release.

(If useful I have started putting my notes about template development at https://antoinegautier.github.io/template-dev-docs/.)

TODO

• [x] Pull last commit from issue1913_g36_final
• [ ] Debug G36 cases with OCT (OCT-4b0cd2bf7110599ad0f5dab28001f198f5f2c661 solves Modelon issue #2022030739000145 that prevented from compiling the templates after refactoring with a master record and no dependency to ExternData.)