feat: workflow for getting wavelength/anode type

[yucongalicechen]

Refer to #155 for more discussion.

Try to get wavelength/anode type from args, then from config files.
C1: User specified nothing. If mu*D is given and xtype is tth, proceed. Otherwise, throw an error.
C2: User specified both, throw an error.
C3: User specified anode type. Check if it is in the database. If not throw an error.
C4: User specified wavelength. Check if it is valid. If not throw an error.

[yucongalicechen]

@till-schertenleib this is kind of the new workflow to get wavelength/anode type from users. Does this make more sense to you more? We decide not to give a default value but just let them enter either wavelength or anode type.