[refactor] Change the regex search to string search

[vodorok]

The regex search() which intent to find codechecker source code comments are swappable with a much faster string.find() method. This will greatly improve performance of retrieving source code comments from the source files.

[vodorok]

Created some profiling of the massStoreRun API endpoint on the server before and after the patch.
These are the stats of the stored report folder:

----======== Summary ========----
--------------------------------------------------------
Number of processed analyzer result files        | 698  
Number of analyzer reports                       | 49916
Number of source files                           | 645  
Number of source files with source code comments | 645  
Number of blame information files                | 0    
--------------------------------------------------------
----=================----
[INFO 2022-10-25 00:20:15] - Compressing report zip file...
[INFO 2022-10-25 00:20:17] - Compressing report zip file done (89.9MiB / 4.7MiB).

Before patch 71.6s:

After patch 30,6s:

The runtime of the modified function can be seen in detail here:

[bruntib]

Wow, this is a great improvement! 😲