feat: add no-runtime-private methods rule

[tobias47n9e]

This optional rule discourages the usage of methods with #-prefix in favor of private method. This encourages users to trust typescript's private keyword and does not prevent debuggers from accessing the method.

Note: I would like to make a similar rule for #-prefixed instance properties. Those are also not accessible by Deno debug, and I think it would be good if the linter could discourage using them.

[0f-0b]

At least V8 provides APIs for debuggers to access private elements. This is what I get using VS Code's built-in debugger with Deno:

[tobias47n9e]

@0f-0b For me it is also about the watch functionality of the debugger. I cannot easily check on nested methods and fields that have the #-prefix at a breakpoint.

this.#database.#somePrivateMethod()

this.#database.#privateField

It could be out of scope for deno lint, but I just wanted to check if something like this would be considered 😄