Refactor chat history UI

[InAnYan]

Preamble

I've spent months making chat history UI. I tried all combinations of possible solutions, but none of them working completely.

The problem

In current version of JabRef, the chat history scrolls down on clicking on message and message deletion. This should not happen.

Also in some cases the ExpandingTextArea is (joke ahead) collapsed. There is no way to explicitly expand it.

Tried solutions

Manual scrolling doesn't work! Changing message components doesn't work, changing parent component (VBox/ScrollPane) doesn't work.

Why ExpandingTextArea is used

We are "forced" to use a text area because of copy feature, because of nearly 10 years old BUG in JavaFX https://bugs.openjdk.org/browse/JDK-8091644.

Moreover, usage of ExpandingTextArea blocks #167.

This refs #169.

Current course of action

1. Focus on more crucial features/bugs.
2. Write an MWE.

[koppor]

@InAnYan Please refine the other options (alternatives) you tried -- You also tried webview. Maybe, you have commits or branches to link?

[koppor]

Explain why ExpandingTextArea and not normal TextArea (if that exists).