Feat/1249 add r interpreter

[hiphof]

rattler-build issue #1249 : Add R as an interpreter

Todo

build section

• print "Hello World"
• make MIT license file
• make custom license file - Should curl be used to get https://cran.r-project.org/web/packages/magrittr/LICENSE. Should curl be in build requirements ?

test section

• format tests>R>libraries, instead of tests>R>uses(the Perl way), source: Add perl test section? #790 (comment)

• find out how to set r flag ('--vanilla'). Or should it uses Rscript -e .?

• consider implementing a 'special' R test that checks if the imports are available and runs R CMD check.

• add e2e test (like Perl)

• docs

Questions:

1. Why there is no build>script>intepreter defined in the Perl test script: https://github.com/prefix-dev/rattler-build/blob/main/test-data/recipes/perl-test/recipe.yaml, like in the Python test script https://github.com/prefix-dev/rattler-build/blob/main/test-data/recipes/python_compilation/recipe.yaml ?