Add the ability to enable an overlay when the plugin switches to search mode

[Gruzchick]

Usually, when you want to jump to some character, you look at it, and you don't see what state the carets are in, to understand that the plugin is activated, because it happens that you accidentally press the wrong combination, and you have to look at cursor and then back to look at the place intended for the jump. This slows things down.

It would be nice to add an overlay, like on this plugin https://plugins.jetbrains.com/plugin/9803-acejump-lite

But in the competitor's plugin, they do not close all editors with an overlay, but only the one in which the cursor is. You could do better than your competitors )

[breandan]

In the next release, if you enable the Show hint with search text option,

AceJump will display the mode and search text in the upper left corner: