Allow loading cached compiled models using hook (#8336)
Allow loading cached compiled models using hook (#8336)

* Initial implementation of loading compiled CustomModel implementation from file

* Added utility to save compiled models

* Provide hook to look up cached implementation

* Add public API to get and set custom model cache

* Reorganized functions

* Pass the CustomModel to the caching hook

mindriot101/bokeh,stonebig/bokeh,ericmjl/bokeh,jakirkham/bokeh,stonebig/bokeh,bokeh/bokeh,timsnyder/bokeh,jakirkham/bokeh,ericmjl/bokeh,dennisobrien/bokeh,mindriot101/bokeh,jakirkham/bokeh,ericmjl/bokeh,mindriot101/bokeh,dennisobrien/bokeh,dennisobrien/bokeh,jakirkham/bokeh,stonebig/bokeh,timsnyder/bokeh,timsnyder/bokeh,stonebig/bokeh,timsnyder/bokeh,bokeh/bokeh,timsnyder/bokeh,dennisobrien/bokeh,bokeh/bokeh,mindriot101/bokeh,bokeh/bokeh,ericmjl/bokeh,ericmjl/bokeh,jakirkham/bokeh,bokeh/bokeh,dennisobrien/bokeh