Provide an easier way to import component specific scripts

[danroth27]

Currently, to load a component specific script (.razor.js) you do something like this:

module = await JS.InvokeAsync<IJSObjectReference>("import", "./{PATH}/JsCollocation2.razor.js");

The "import" convention is a bit awkward to remember and you also need specify the script path. Could we make this simpler? Maybe provide an ImportAsync overload? Or maybe a declarative model, like this (suggestion from @DamianEdwards)?:

[JsModuleImport]
private IJSObjectReference? Module { get; set; }

@MackinnonBuck did some prototyping for component specific styles that work across render modes a while back that might also be worth considering: MackinnonBuck/blazor-js-components

[maraf]

One of the problems with imports is that they have a different lifetime then the component. You most typically want to import the scripts once for all instances of the component, but there might be cases when that is not true. That mostly touches the declarative mode idea. In runtime JavaScript interop we have JSHost.ImportAsync API.

Pavel: If we ever implement multi threading, the import needs to happen on every thread.

[samanson123]

+1 for @MackinnonBuck BlazorJSComponents.

Given the component driven nature of Blazor, I believe his solution works well in a Blazor context and would be worthwhile considering being absorbed into the framework for those that want component driven JS files.