Implement rawRR backend to read data from raw files

[hechth]

Use the rawRR package to implement a backend reading .raw files into aplcms. The package is described here (https://pubs.acs.org/doi/10.1021/acs.jproteome.0c00866) and is available on bioconductor - there is also a package https://github.com/fgcz/MsBackendRawFileReader to read this with spectra, but I'm not sure if this is actually easier than using the rawrr package directly (https://github.com/fgcz/rawrr/).

A tutorial on how to use rawRR is available here. The function should also be implemented in the load.lcms.R file and should also come with unit tests of course!

Steps

• do the tutorial (using windows subsystems for Linux)
• try reading some of our raw files which we have on SALLY
• Add a RAW file to the umsa-files repo as testdata
• Implement a unit test for RAW files for load.lcms.R
• Add rawRR to suggested packages
• Implement the load.lcms.R function for raw files of the rawRR package is installed using the require function in R

Possible problems

• rawRR requires some DLLs and runs on mono, which means it might not work on linux
• the package might not be available via conda
• the package might not be compatible with other dependencies