Friendly error message when importing node built-in modules without a node: prefix

[dsherret]

This depends on support for node: modules in #16223

When built-in Node.js modules are imported without node: prefix a friendly error message is shown:

import { readFile } from "fs";

Add a "node:" prefix to the following import:
  import { readFile } from "fs";
Like this:
  import { readFile } from "node:fs";

This is only relevant to the user code - dependencies imported with npm: specifiers will have these modules available in both forms.

[aapoalas]

This should probably be an LSP FixIt as well.

[albnnc]

Continuing roadmap discussion, is this going to support searching in different URI scopes like deno: or custom: (in case they are going to be implemented)?

---

Currently, we have the following behaviour:

➜  ~ deno repl -A
Deno 1.29.4
exit using ctrl+d, ctrl+c, or close()
> import * as fs from "fs"
Uncaught TypeError: Relative import path "fs" not prefixed with / or ./ or ../ from "file:///Users/albnnc/$deno$repl.ts"
    at async :2:12
>

What about unbiased message like "Hey, we got bare specifier, do you want to add import map entry?"? This would advocate Node less, which is good, in my opinion.

[dsherret]

Continuing roadmap discussion, is this going to support searching in different URI scopes like deno: or custom: (in case they are going to be implemented)?

Not for this issue. This is just for known node built-in modules like "fs" -> "node:fs" in order to help guide people on how to run Node code in Deno. This is instead of supporting bare specifiers like "fs", which would not be great IMO.

What about unbiased message like "Hey, we got bare specifier, do you want to add import map entry?"? This would advocate Node less, which is good, in my opinion.

I think this should be more explanatory for any import that matches a node built-in module's bare specifier since it would be more helpful to give Node users a clear path to getting their existing code running in Deno. Obviously we'd like users not to use node: imports, but some people might have a lot of existing code using that.