feat: cache node modules

[cazala]

This PR adds two steps to the installation of the extension dependencies:

1. First, it restores the node_modules from the global cache (if it exists) by copying the node_modules from {globalStorage}/.cache/node_modules into {extensionPath}/node_modules
2. Second, it installs the extension's dependencies by running npm install
3. Third, it copies the freshly installed node_modules into the global cache at {globalStorage}/.cache/node_modules to keep the cache updated.

This makes the installation process faster for future version because it doesn't run the npm install on an empty node_modules but instead it keeps the ones from the previous version.

[github-actions[bot]]

Test this pull request

• The editor-sdk7 extension can be tested in VSCode by downloading this package and running:

  code --force --install-extension editor-sdk7.vsix