Allow to output the SPDX identifier

[RHeynsZa]

Describe the solution you'd like
Can we have some sort of a lookup to make sure that license output matches SPDX codes?
As this is the standard, I assume that a lot of people will be wanting to use this

Describe alternatives you've considered
Writing my own lookup, but that seems redundant

Additional context
Add any other context or screenshots about the feature request here.

[dd-jy]

@RHeynsZa
We have a plan to generate a result file with spdx format.
Currently, most package managers in FOSSLight Dependency Scanner take the license name through manifest file.
And some package managers doesn't support the SPDX identifier.
If the SPDX identifier is invalid, do you have any ideas about changing it?