Share RawBatchEvent forgery for tests between the modules

[0xnm]

What does this PR do?

Just a minor improvement to share RawBatchEvent forgery, so that is can be used in tests in different modules.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[xgouchet]

Nice work

[codecov-commenter]

Codecov Report

Merging #1680 (fa17561) into nogorodnikov/rum-321/reduce-view-events-in-upload-pipeline (4a3f24c) will decrease coverage by 0.05%.
The diff coverage is n/a.

@@                                      Coverage Diff                                       @@
##           nogorodnikov/rum-321/reduce-view-events-in-upload-pipeline    #1680      +/-   ##
==============================================================================================
- Coverage                                                       83.71%   83.66%   -0.05%     
==============================================================================================
  Files                                                             462      462              
  Lines                                                           15843    15840       -3     
  Branches                                                         2363     2362       -1     
==============================================================================================
- Hits                                                            13262    13252      -10     
- Misses                                                           1943     1948       +5     
- Partials                                                          638      640       +2     

see 15 files with indirect coverage changes

The base branch was changed.