master issue tree expansion woes:

[duncdrum]

There are a number of problems / bugs with the tree view of this extension. Not all of these are probably related by the same underlying technical or code issue, but i think its a good idea to start collecting them in a central place.

1. GUI expansion click vs double-click
   A double-click should not trigger click expansion. The UI should be able to clearly distinguish between the two events. Needs tests. Also not that double-click for properties does not apply to other tree items, only the root server connection entry, i suggest only showing properties on right-click for the whole tree.

Screen.Recording.2021-09-14.at.14.10.49.mov

2. Tree expansion consistency
   seems to work but needs tests for different api endpoints. I.e. the last expansion is recalled when collapsing and expanding ancestor items.

Screen.Recording.2021-09-14.at.14.29.07.mov

3. Missing UI indicators for expand/collapse

see VSC, no reason to use visual clues to inform users of what is what. Probably better for accessibilty as well.

4. DOM is not nested
   having a flat html representation of the tree items is very counter-intuitive, it will also not play nicely with other theia vsc extensions, which all expect nested trees to be nested html.

see #411 this html fragment

to the 4 entries Servers, localhost, db, Security

5. Insta collapse when creating a new connection

Screen.Recording.2021-09-14.at.14.10.49.mov

[duncdrum]

see #413

[ccheraa]

The missing indicators problem is tracked down to PR #472, I still don't know how exactly that PR affected the indicators.
Interestingly, when you open a document from the tree, the indicators are back again.