fix: align viewsWelcome behavior to VS Code

[dankeboy36]

Motivation

This PR patches the default behavior of the viewsWelcome and aligns it to VS Code, most notably, it honors the enablement property of the viewsWelcome contribution (eclipse-theia/theia#14309) to provide dynamic UX via a VS Code when context.

Originally from the Arduino Forum:

I know it's just static info with links... but if could it could be dynamic, the ideal GUI would disable the 3 sketch buttons until the key is created.

viewsWelcome.mov

Change description

• patches the VS code scanner to read the enablement property.
• rewrite the view welcome tree behavior to match VS Code (https://github.com/microsoft/vscode/blob/56b535f40900080fac8202c77914c5ce49fa4aae/src/vs/workbench/browser/parts/views/viewPane.ts#L228-L299)

Other information

Ref: eclipse-theia/theia#14309

Package index for the 1.60 Teensy core: https://www.pjrc.com/teensy/td_160-beta3/package_teensy_0.60.3_index.json

Reviewer checklist

• PR addresses a single concern.
• The PR has no duplicates (please search among the Pull Requests before creating one)
• PR title and description are properly filled.
• Docs have been added / updated (for bug fixes / features)

[dankeboy36]

The build failure is most likely unrelated to the proposed changes; the CI must not sign the builds from forks:

Custom windows signing was no performed one of the following variables was not provided: SIGNTOOL_PATH (C:/Program Files (x86)/Windows Kits/10/bin/10.0.19041.0/x86/signtool.exe), INSTALLER_CERT_WINDOWS_CERT (C:/Users/Utente/AppData/Local/Temp/cert.cer), CERT_PASSWORD (), CONTAINER_NAME ()