Add "reset to default" button for "Cite command"

[koppor]

We need a button "Reset to default" for the "Cite command". A user might put arbitrary strings there - and we need to support them to go back to the default easily. The default is \cite{key1,key2}.

The icon and the label text can be found in "Citation key patterns":

Refs #10568

[JonathanRech]

Hello @koppor , I would like to try work on this issue.

For clarification: I should add a Button to "Cite Command" that uses the icon and labeltext like in "Citation key patterns"

[SUPWEZZ]

Hi @koppor, since the previous two issues were unassigned, may I do this new issue?

[Siedlerchr]

@JonathanRech was first

For clarification: I should add a Button to "Cite Command" that uses the icon and labeltext like in "Citation key patterns"

Not only the button but also the functionality needs to be implemented. The value of the pattern should be reset to the default value.

[calixtus]

Why an extra button to reset this? Maybe a tooltip or an example string on the right is better.
The reset functionality is provided by the preferences dialog itsellf and the current implementation with the defaults map is soon to be replaced anyways.

[Siedlerchr]

@calixtus You can reset the entry preview as well. Same for custom entry types. So this is totally fine. And button we mean a simple icon.