fix: add missing @param javadoc, null check, and remove leftover dev comments

[Muralikrishna23]

1. AuditService.java

   • Added missing @param sortOrder in Javadoc for both getAllRevisions() overloads

2. AuditServiceImpl.java

   • Added null check in mapAuditEntitiesToDetails() to prevent
     NullPointerException when null list is passed

3. AuditlogwebController.java

   • Removed leftover inline dev comment "// <-- New param" from line 164

[Binayak490-cyber]

Hi @Muralikrishna23, have you gone through this before raising PR - https://openmrs.atlassian.net/wiki/spaces/docs/pages/25477199/Pull+Request+Tips