List multiple weak supervision algorithms

[jhoetter]

Is your feature request related to a problem? Please describe. Weak supervision is not only one specific algorithm, but you can actually choose from a set of formulas. Let users decide which algorithm they want to pick :)

Describe the solution you'd like General SGD variant, Triplet-based, etc.

Also, for the sigmoid confidence estimation, enable users to provide parameters for c and k (see weak-nlp library)

Describe alternatives you've considered Users could have a programmatic interface with template-injected code for weak supervision. But this is only for high customization and most likely not required at the moment.

Additional context -