Inject laser glitches

In https://gitlab.in2p3.fr/lisa-simulation/glitch/-/merge_requests/20, we propose to add laser glitches to the list of available injection points. Based on the choice of units made there, we should read the new injection points in lisainstrument with the correct scaling.

• Injection point: local_carrier_fluctuations and local_usb_fluctuations
• Coupling factor: [to be defined, depends on the units chosen in lisaglitch]
• Datasets in glitch file: laser_ij or laser_i depending on three_lasers parameter; only read (and inject) the relevant ones depending on the value of this parameter