allow to configured database version via ENV var

[kevinpapst]

Description

Without configured DATABASE_URL it was not possible to clear/warmup cache.

It could be faked by configuring a database url with version string:

DATABASE_URL=mysql://anonymous@localhost?serverVersion=mariadb-10.4.13

or now it can also be defined via the DATABASE_VERSION env var:

DATABASE_ENGINE=mysql
DATABASE_VERSION=mariadb-10.4.13

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 #2055 into master will increase coverage by 0.00%.
The diff coverage is 76.47%.

@@            Coverage Diff            @@
##             master    #2055   +/-   ##
=========================================
  Coverage     93.27%   93.27%           
- Complexity     5788     5790    +2     
=========================================
  Files           530      530           
  Lines         17538    17542    +4     
=========================================
+ Hits          16359    16363    +4     
  Misses         1179     1179           

Impacted Files	Coverage Δ	Complexity Δ
...endencyInjection/Compiler/DoctrineCompilerPass.php	76.59% <76.47%> (-0.15%)	22.00 <14.00> (+2.00)	⬇️
src/Repository/TimesheetRepository.php	89.54% <0.00%> (+0.19%)	133.00% <0.00%> (ø%)