Custom panel to recommend a JDK download if it does not exist.

[NikolasKomonen]

In the case that a JDK cannot be found, we currently have a small popup box to link to a page to download a JDK.

A nicer/easier implementation was done for the Java-extension pack.

Here is how they did it: microsoft/vscode-java-pack#142 (comment)

Update: indicated below, only need to write it if it is not released as an npm module. If it is eventually released then simply setup the code to be able to use it.

[fbricon]

We discussed this with Microsoft, ideally that JDK management page should be published as an npm module, so that any project that requires Java can use it. Similar comment is done in the referenced issue. cc @yaohaizh

[BinToss]

This project no longer requires Java. Is this issue still relevant?