Replace large dictionaries with enums

[jondoesntgit]

There are several places where large dictionaries are used:

• lia status bytes
• lia time constants
• lia sensitivities
• awg waveforms

These could be replaced by enum classes.

[jondoesntgit]

@shinjoe also suggests making direction of the rotation stage ('cw' or 'ccw') an enum