cleanup global context

[kevinpapst]

Description

This PR adds further code cleanup.

Previously there were some objects used, which were using the global context from Symfony.
These have to be removed one-by-one and will replaced with runtime code.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I verified that my code applies to the guidelines (composer code-check)
• I updated the documentation (see here)
• I agree that this code is used in Kimai and will be published under the MIT license

[codecov]

Codecov Report

Merging #1943 into master will increase coverage by 0.03%.
The diff coverage is 88.88%.

@@             Coverage Diff              @@
##             master    #1943      +/-   ##
============================================
+ Coverage     93.32%   93.36%   +0.03%     
- Complexity     5311     5316       +5     
============================================
  Files           502      503       +1     
  Lines         16370    16380      +10     
============================================
+ Hits          15278    15293      +15     
+ Misses         1092     1087       -5     

Impacted Files	Coverage Δ	Complexity Δ
src/Form/Extension/UserExtension.php	100.00% <ø> (ø)	3.00 <0.00> (ø)
src/Controller/TimesheetAbstractController.php	86.82% <33.33%> (ø)	74.00 <0.00> (ø)
src/Invoice/ServiceInvoice.php	87.70% <80.00%> (+0.33%)	71.00 <3.00> (+2.00)
src/API/BaseApiController.php	100.00% <100.00%> (ø)	3.00 <3.00> (?)
src/API/ProjectController.php	96.57% <100.00%> (ø)	43.00 <1.00> (ø)
src/API/TimesheetController.php	96.42% <100.00%> (+0.01%)	82.00 <0.00> (ø)
src/Controller/CalendarController.php	100.00% <100.00%> (ø)	5.00 <3.00> (ø)
src/Controller/InvoiceController.php	79.42% <100.00%> (ø)	52.00 <1.00> (ø)
src/Controller/ProjectController.php	91.47% <0.00%> (+2.24%)	55.00% <0.00%> (ø%)