Get request variables from query instead of request.

[irfan-synerzip]

Q	A
Bug fix? (use the a.b branch)	[ ]
New feature/enhancement? (use the a.x branch)	[ ]
Deprecations?	[ ]
BC breaks? (use the c.x branch)	[ ]
Automated tests included?	[ ]
Related user documentation PR URL	mautic/mautic-documentation#...
Related developer documentation PR URL	mautic/developer-documentation#...
Issue(s) addressed	Fixes #11996

Description:

Cherry picking #11760 changes to fix the issue for Mautic 4.4

[escopecz]

The code changes make sense. They are same as in the M5 PR and there is no reason they would work differently

[escopecz]

re-opening to trigger CI jobs

[codecov]

Codecov Report

Merging #12002 (c8cf33c) into 4.4 (853c13b) will increase coverage by 0.02%.
The diff coverage is 13.33%.

@@             Coverage Diff              @@
##                4.4   #12002      +/-   ##
============================================
+ Coverage     50.26%   50.29%   +0.02%     
- Complexity    35432    35446      +14     
============================================
  Files          2145     2145              
  Lines        106366   106420      +54     
============================================
+ Hits          53470    53524      +54     
  Misses        52896    52896              

Impacted Files	Coverage Δ
...p/bundles/LeadBundle/Controller/AjaxController.php	6.69% <0.00%> (ø)
...bundles/PluginBundle/Controller/AjaxController.php	0.00% <0.00%> (ø)
.../bundles/EmailBundle/Controller/AjaxController.php	32.00% <66.66%> (ø)

... and 2 files with indirect coverage changes