Separate selection for inpainting model

**Is your feature request related to a problem? Please describe.**
Since you select the model in a separate toolbar it gets confusing when things don't work after jumping between eg. tex2img and inpainting.

**Describe the solution you'd like**
Give the inpainting menu a separate model selector.

**Describe alternatives you've considered**
It could also work by having a default option that allows for binding models for use with the inpainting