Introduce View Models

[kennsippell]

Introduces typed view models #270

Example:

This adds ViewModels for anything which is rendered directly by a route.

This is an example view model in liquid/auth/index.ts:

export type AuthFormViewModel = {
  domains: AuthenticationInfo[];
  error?: string;
};

export type AuthViewModel = {
  logo: string;
} & AuthFormViewModel;

And the route looks like this:

    const viewModel: AuthFormViewModel = {
      domains: Config.getDomains(),
      error
    };
    return resp.view('src/liquid/auth/authentication_form.liquid', viewModel);

• Renames html to liquid Rename all template extensions to .liquid #280
• Consolidates include and render to use render for everything
• Moves view and routes from /new and /edit to be under /multiplace/new and /multiplace/edit
• Component which are rendered by routes and not by views are moved out of the components folder
• Add documentation of expected information at the top of all components which don't have a viewmodel

[kennsippell]

I didn't see #290 when I approached this work. I'll rebase this to be based off that work.