Update package.json to include newer Theia packages

[t1m0thyj]

The current selection of Theia packages in package.json.template is fairly slim and comes from https://github.com/theia-ide/theia-apps/blob/master/theia-docker/latest.package.json

Investigate including a more complete set of Theia packages, for example:

• https://github.com/theia-ide/theia-apps/blob/master/theia-full-docker/latest.package.json
• https://github.com/eclipse-theia/theia-blueprint/blob/master/applications/browser/package.json

[t1m0thyj]

Moved to zowe/zowe-sample-dockerfiles#3