includeScript() and inlineStyle() of external resources

[dgp1130]

Currently includeScript() and inlineStyle() do not have well defined semantics for importing files outside the current workspace. We should define exactly what syntax they should use and how those dependencies should be specified.

ts_project() / js_library() can support external dependencies as long as they are wrapped in an NPM package, and then they are importable by the package name. We could consider extending those semantics for css_library() dependencies and prerender_component() dependencies.