Introduce alternatives to right-click only functions

**Issue by [JHCD](https://github.com/JHCD)**
_Wednesday Feb 22, 2017 at 11:01 GMT_
_Originally opened as https://github.com/CQUI-Org/cqui/issues/315_

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Using a tablet with finger or pen has the disadvantage that right-clicking isn't possible.
It looks like that Civ VI doesn't support the MS implementation of "pen right-clicking".

- [ ] Delete item in production queue
- [ ] Delete item in sidebar

to be continued...

Start by locating the Lua UI implementations for the production queue and sidebar, then inspect how their current right-click actions are wired. Define accessible alternatives for deleting items in both places and verify them with tablet or pen input in Civilization VI; the checklist should be complete when both actions work without right-clicking.

Written by the indexing model from the issue text.