UI/UX improvements: a more orderly toolbar

[smiakchilo]

Rework appearance of the toolbar by

• grouping functionally adjacent buttons (e,g, "Replace by pattern" and "Fix broken"). Possibly introduce split buttons (dropdowns)
• make all buttons appear in the same toolbar (but disabled if not applicable to the currently selected entry)
• assigning the 'primary' style to "more important" elements and otherwise
• getting rid of redundant and duplicating elements (currently, there are two different clickable elements with the meaning of "Select all").

Additionally: revise the design of the pop-up windows opened from the toolbar. Make sure that buttons are dynamically enabled/disabled as a result of text change and not "on blur". (Currently, the "OK" button that depends on a text field may look "disabled" even as the text field gets some text and until they actully click on the button. That is because it changes on "blur" event and not on "keydown"/"keypress").