Plugin update won't work with locally developed plugin

Hello,

Description

I created a tns app with tns create MyTnsApp --tsc and a plugin (with nativescript-plugin-seed) for it and put it to the plugins folder.

Here is the directory tree:

├── app
│   ├── package.json
│   └── <other files>
├── hooks
│   └── < ... >
├── node_modules
│   └── < ... >
├── package.json
├── platforms
│   └── < ... >
└── plugins
    └── nativescript-myplugin
        └── src
            ├── package.json
            └── < ... >

I can successfully add the plugin via: tns plugin add plugins/nativescript-myplugin/src/

I can successfully remove the plugin via: tns plugin remove nativescript-myplugin

The problem

Using tns plugin update nativescript-myplugin removes the plugin I want but it tries to get the source from https://registry.npmjs.org/nativescript-myplugin which drops a 404 error, of course.
So, the install fails.

Using tns plugin update plugins/nativescript-myplugin/src/ says "Plugin "plugins/nativescript-myplugin/src/" is not installed."

The expectation

I would like to update my plugin even if I develop it locally.
Either giving the path of the plugin or the name of it,update should work without a problem.

Start by reproducing the behavior with tns plugin add plugins/nativescript-myplugin/src/, then run both tns plugin update nativescript-myplugin and the path-based update command. Trace the tns plugin update CLI entry point and compare how installed local plugins are recorded and resolved. Done means updating the local plugin by name or path without fetching an unavailable npm package.