[GSoC][Patch] Automatic Mode Detection V1

Dear all,

This is my first patch of my GSoC project, query tool automatic mode
detection.

In this patch, the initial (basic) version of the project is implemented.
In this version, query resultsets are updatable if and only if:
- All the columns belong to a single table
- No duplicate columns are available
- All the primary keys of the table are available

Inserts, updates and deletes work automatically when the resultset is
updatable.

The 'save' button in the query tool works automatically to save the changes
in the resultset if the query is the updatable, and saves the query to a
file otherwise. The 'save as' button stays as is.

I will work on improving and adding features to this version throughout my
work during the summer according to what has the highest priorities
(supporting duplicate columns or columns produced by functions or
aggregations as read-only columns in the results seems like a good next
move).

Please give me your feedback of the changes I made, and any hints or
comments that will improve my code in any aspect.

I also have a couple of questions,
- Should the save button in the query tool work the way I am using it now?
or should there be a new dedicated button for saving the query to a file?

- What documentations or unit tests should I write? any guidelines here
would be appreciated.

Thanks a lot!

--
*Yosry Muhammad Yosry*

Computer Engineering student,
The Faculty of Engineering,
Cairo University (2021).
Class representative of CMP 2021.
https://www.linkedin.com/in/yosrym93/