String identifier for user bins

[pirovc]

I suggest to have an option to tag user bins with a name/identifier. That would facilitate integration with other tools and downstream analysis. Currently, AFAIK, it accepts in the raptor prepare --input:

filename
or
filename1 <space> filename2 <space> filename3

The first filename of each line is used as the "identifier" of the bin. I would suggest adding two new modes:

filename <tab> identifier
and
filename1 <space> filename2 <space> filename3 <tab> identifier

Where instead of using the first filename it uses the last col (tab separeted) as an identifier for each bin.

Example: building the HIBF at species level (each species are formed by several files). Here the species taxid would be used as identifier. When I do the search, I can directly get the species out.

[eseiler]

Idea:

filename struct

struct files
{
    std::vector<std::string> filenames{};
    std::string identifier{};
}

Index stores std::vector<files>

Identifier with tab in output minimiser.list