Add ability to select all/copy/search/goto in editors

[Mingun]

Is your feature request related to a problem? Please describe.
When you blaming or see diff of big file, you may want to go to the specific line / text, related to context. Currently it is not possible, and moreover, you even cannot select all content by shortcut and copy it to the editor where you can perform search.

Describe the solution you'd like
Add standard shortcuts:

• Ctrl+A for select all
• Ctrl+C for copy
• Ctrl+F for search
• Ctrl+G for go to line

Describe alternatives you've considered
None