Fix Query Generator backticks

[faissaloux]

Hellooo 👋🏻

In this PR I have fixed the issue with Query Generator that doesn't escape all the backticks when we have more than one.
It only escapes one backtick (The first one), so the issue appears if we have multiple backticks.

Like you can see in the example I'm showing you 3 different columns which contain different number of backticks:

• `col_one: contains one backtick which is escaped as expected.
• `col_two`: contains two backticks which only the first was escaped.
• `col_`three`: contains three backticks which only the first was escaped.

This generates a non-valid query.

Before

After

All backticks escaped as expected.

Server configuration

• phpMyAdmin version: 5.2.2-dev, 6.0.0-dev