Show full (multiline) Message in Stash Apply/Drop dialogs

[goran-w]

This is a follow-up tweak for #1426 - the Apply and Drop dialogs for stashes now need to show the full (potentially multi-line) Message of the stash.

Example stash, with multiline Message:

This causes vertical offset here (in Apply dialog), since the text area is not prepared for multi-line content:

Similarly, the full message should be visible here (in Drop dialog), as well:

Even long single-line messages are cut-off without ellipsis etc, so scrollbars would be helpful (in both horizontal and vertical directions, as needed) :

(NOTE: Alternatively, a tooltip could be added to display the full Message when hovering over the truncated one...)

[love-linger]

Fixed.