Task 23: Hide additional section panel.

Removed it fully, instead of hide.
Add letter table view. Also add email and sheet config.
Config implemented.

Start page became email config. Button implemented. Mess code deleted.
Bug: Decrease page refresh time during the work.
Task 30: Add editable future to datatable.

Add plugin.
Added required libraries for inline update.
Editable pack for web project.
Formatter applied.
Move out method to main.js.
Bug: prevent clicking if form in load.
Fix: Bug : Updated date foes to wrong columns.