[pgAdmin4][Patch]: RM#1423 - SQL panel should be greyed in Edit Data mode

Hi

Please find the attached patch with solution:

1. Introduced a new class 'cm_disabled' with css property
background-color to '#EEEEE'
2. Query tool in edit mode, add the class 'cm_disabled' to set
background color to dark and set the cursor property to 'nocursor' to
disable editor.
3. Increased the query tool title padding to fix the issue of whitespace
below the title.

Please review.

Thanks,
Surinder Kumar