fix: load vsix with no publisher

[amiramw]

This is relevant for extension development flow.
Currently when running 'yo code' the extension is created without publisher.
VS code 'Run Extension' launcher is able to run/debug it.
In theia prior to this fix it caused TypeError: Cannot read property 'toLowerCase' of undefined

Signed-off-by: Amiram Wingarten amiram.wingarten@sap.com

What it does

Fix run hosted plugin flow when publisher is missing on the extension project selected.

How to test

1. Run yarn global add yo generator-code
2. Run yo code
3. Run: F1 -> "Hosted Plugin: Start Instance"
4. Select the project created
5. Hosted plugin should now have command "Hello World" and running it create a user notification

Prior to that fix the extension could not be deployed on backend with this stack trace:

root ERROR Failed to load plugin metadata from "/workspace/test" TypeError: Cannot read property 'toLowerCase' of undefined
    at VsCodePluginScanner.getModel (/workspace/theia/packages/plugin-ext-vscode/lib/node/scanner-vscode.js:73:34)
    at MetadataScanner.getPluginMetadata (/workspace/theia/packages/plugin-ext/lib/hosted/node/metadata-scanner.js:46:28)
    at HostedPluginReader.readMetadata (/workspace/theia/packages/plugin-ext/lib/hosted/node/plugin-reader.js:171:43)
    at HostedPluginReader.<anonymous> (/workspace/theia/packages/plugin-ext/lib/hosted/node/plugin-reader.js:139:64)
    at step (/workspace/theia/packages/plugin-ext/lib/hosted/node/plugin-reader.js:57:23)
    at Object.next (/workspace/theia/packages/plugin-ext/lib/hosted/node/plugin-reader.js:38:53)
    at fulfilled (/workspace/theia/packages/plugin-ext/lib/hosted/node/plugin-reader.js:29:58)

root ERROR Could not initialize contribution TypeError: Cannot read property 'model' of undefined
    at HostedPluginReader.<anonymous> (/workspace/theia/packages/plugin-dev/lib/node/hosted-plugin-reader.js:87:44)
    at step (/workspace/theia/packages/plugin-dev/lib/node/hosted-plugin-reader.js:57:23)
    at Object.next (/workspace/theia/packages/plugin-dev/lib/node/hosted-plugin-reader.js:38:53)
    at fulfilled (/workspace/theia/packages/plugin-dev/lib/node/hosted-plugin-reader.js:29:58)

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

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[benoitf]

Thanks !