FHI aims parser out of date

The FHI aims parser fails to capture the Fermi level in the last version (v210716). The output change from | Chemical potential (Fermi level) in eV : -.61046893E+01 to | Chemical potential (Fermi level): -6.10468056 eV. Note that the parser captures both the value and the unit, which have swapped order now.

I see 2 workarounds:

1. Extract the version number first and then define the regex based thereon. Currently, the parsers extract the version together with other quantities, after having defined these at the same level.

2. Incorporate the option for a list of regex patterns to be tried (at class Quantity in nomad/parsing/file_parser/text_parser.py).

This was first brought up in issue #868 (closed).