Missing features in the pybind API

[baconpaul]

Pybind isn't quite complete. Here's the list of bits we need. This issue will happen over time but put them all here.

wavetable

• set patch wt from path.
• extract wt binary from a patch

We are good if you can semantically write

s = surge
s.set osc 1 type (wt)
s.set wt 1 (/path/to/factor/foo/sin.wt)
s.save patch

and the saved patch is all set up

Param features

• extend / can extend
• temposync / can tempo sync
• deform / can deform
• extend / can extend
• portamento options (low prio but why not)

Formula modulator

• get set lua body

mseg modulator

• data structure as table
• an isvalid