Add a hash of arbitrary record info to accessionBuilder

[meowcat]

We already have info("...") which copies arbitrary metadata into the accession tag. Add info_hash("...", digits = 3) to get this as a fixed-width code.

[tsufz]

@meowcat Okay, will try this. I guess, I need to add this to the settings?

[meowcat]

Oh I was going to do this rightaway except if you're in the flow :)

[tsufz]

No rush, I can run the [M+H] first, but it says that the information comes from AC$ or CH$, but for example, the ion is in MS$?

[meowcat]

Hi, this is independent of your other request, we need info("AUTHORS") since we will have the same compound measured by different groups...

[meowcat]

Uff, I see that info() is pulling from variables$metadata rather than spectrum@info as I thought (but this matches the documentation in RMB_options.ini). I guess I will just fill up the metadata with more values?

[meowcat]

Done in #346