MatthewHeun/Recca: v0.1.38

Recca 0.1.38 (2022-04-02) Removed unnecessary assertion that matsbyname is available in aggregation functions. Eliminated finaldemand_aggregates_with_units(), because nobody was using it. New function calc_eta_pfd() calculates gross and net efficiencies from primary to final demand. New function region_aggregates() calculates regional aggregates according to columns in a data frame. New look for pkgdown website. extend_to_exergy() gains new arguments mat_piece, phi_piece, notation, and prepositions to enable more flexible row and column name matching between the various matrices and phi vectors. In addition, extend_to_exergy() now uses matsbyname::vec_from_store_byname() internally to correctly handle hatized vector multiplication. Many new tests for new features. Now up to 556 tests, all passing. Test coverage remains at 100 %