447 coda transformations add selection of columns/attributes of the input data

[msorvoja]

Fixes #447

I did not modify Single ILR as subcomposition parameters are already required.

And about PLR: I edited it so that if user selects some columns for the transformation, the numerator is placed on the first column and the selected columns on its right side so that the algorithm works. I'm not certain if it causes any errors in the results. Could @jtlait or @em-t verify whether this is okay or not?

[jtlait]

I am not too familiar with PLR, so maybe @em-t or @chudasama-bijal can comment on this. About another thing regarding column selection, check_in_simplex_sample_space cannot be run at first when columns are selected. If input dataframe contains some additional variables besides geochemical variables and only geochemical variables are chosen, then check_in_simplex_sample_space should be run only for the selected geochemical data.

[em-t]

I started to look at this today, but didn't quite have time for a proper review. I'll return to this tomorrow!

[chudasama-bijal]

I will take a look at the coda related issues next week.