Update Stan to 2.36.0

[WardBrian]

Stan 2.36 released this morning.

This PR:

• Updates the backend to use a newer commit of tinystan which includes Stan 2.36
• Updates our copy of stanc.js

Also updates the docker image to use a newer emscripten and the new repo link for TBB.

To verify, you can use a new function like

generated quantities {
  real rng = beta_neg_binomial_rng(0.2,0.4,0.3);
}

[WardBrian]

@magland how manual is the process to update the public server?

[jsoules]

Checked out the branch and started a local gui server.

Added the suggested generated quantities block to the end of the linear regression model.

While connected to public server (old version of Stanc), attempting to compile returns a syntax error (this is expected).

Ran a local compilation server with the docker image provided in this branch. When connected to this, everything works as expected and the rng field is populated.

Note: the first time I tried to sample after compiling, I got some kind of blank screen. Didn't have the log up so I don't know what happened--when I reloaded and reran, everything went fine.