feat(init): support initializing npm projects

[bartlomieju]

This commit adds support for deno init npm:<package>.

Running this will actually call to npm:create-<package> package that
is equivalent to running npm create <package>.

User will be prompted if they want to allow all permissions and lifecycle scripts
to be executed. It was discussed internally if we should accept permission flags here
but it will be really cumbersome and in most cases these creation scripts need to do
a lot of crazy stuff including reaching out to networks, reading and writing to file system,
reading env vars and spawning subprocesses.

Closes #26461

[bartlomieju]

BLOCKER FOR LANDING:

Do the confirmation prompt if user wants to allow all permissions and post-install scripts.

[bartlomieju]

If user doesn't grant it, we should print a message how this could be executed manually using deno run subcommand - eg. deno run npm:create-vite

[marvinhagemeister]

Tried out the changes in this PR but ran into an issue where it doesn't seem to install the create-<package> dependency.

1. Create an empty folder and cd into that
2. Run deno-git init npm:preact

Output:

$ deno init npm:preact
error: Could not find a matching package for 'npm:create-preact' in the node_modules directory. Ensure you have all your JSR and npm dependencies listed in your deno.json or package.json, then run `deno install`. Alternatively, turn on auto-install by specifying `"nodeModulesDir": "auto"` in your deno.json file.

EDIT: Ignore what I wrote. I had a package.json in a parent directory.

[bartlomieju]

Thanks, I know what the problem is, will fix it tonight.