[GSoC][New Feature] Editable and Read-only Columns

Hi, hackers !

Please find attached a work-in-progress patch adding a new feature to the
Query Tool on top of updatable result-sets.

This patch allows individual columns of an updatable result-set to be
editable or read-only. This allows for a wider variety of updatable
result-sets, for example:

- Result-sets with duplicated columns.
- Result-sets with renamed columns (if a column is renamed to a primary key
name, the real primary key can be correctly identified) .
- Result-sets including columns that are not selected directly from a table
(e.g concatenation of 2 columns or system columns).

In the above cases, these columns would be read-only while other columns of
the result-set are editable. Editable/Read-only columns are identified by
icons and tooltips in the column header.

This is still a work-in-progress, updates to tests and documentation is
still due. Looking forward to your thoughts and feedback!

Also, do you think the editable/read-only icons should apply in both
View/Edit Data and Query Tool for consistency? or hidden from View/Edit
Data as all columns are editable anyway?

Thanks.

--
*Yosry Muhammad Yosry*

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