Tab completion for files for comma separated values

[preshanth]

When interacting with the interface for entering a comma separated list of files. The tab completion only works on the first file. The rest don't show up. This is a feature request to enable that.

[sanbee]

When strings are ingested via clgetValp(string&, string& or array<string>&, int) signature, starting a file name with a path (e.g. with a / or ./) triggers the filename completion algorithm. This is true for the elements of a comma-separated list input (val0, val1, val2,...). However, currently, you need a blank after each comma for this to trigger. This is limitation of the parafeed library and I'll look into fixing that. In the meantime, use the above workaround.