Add FIM check_md5sum IT tests

[Deblintrake09]

Target version	Related issue	Related PR/dev branch
4.5.0	wazuh/wazuh#16625	wazuh/wazuh#16718

Description

This Issue aims to add test support for FIM md5_sum calculations and the check_md5sum tag.

Proposed test cases

File md5_sum is properly calculated

Scenario Outline: When a file in a monitored folder is modified, the new `md5_sum` is calculated and reported

Given a folder is being monitored with check_md5sum='yes'
When an already detected file is modified
Then the modified alert is generated and it contains the new `md5_sum`

Considerations

• Cases should be generated for all three monitoring modes