Multiple improvements

# What is currently missing?

- In ManageDatabase, see the possibility of changing List to Set.
private static Map>> usersPerTeamAndTenant = new HashMap<>();
- ~~for pagination requests, try using this logic, and also see if that logic can be re-used across all services
getOperationalRequestsPaged int i = Math.max(0, startVar); i < Math.min(lastVar, totalRecs)~~
- In OperationalRequest, there are several transient variables. Create a base class, and adapt it across all other similar classes.
@Transient private String environmentName;
- ~~A pojo would be nice in these patterns, which is done in several code blocks
hashMap.put("result", ApiResultStatus.SUCCESS.value);~~
- getEnvDetails method in commonUtilsservice class should be reused across all service classes
- getPrincipal() method is in all service classes, which can be moved to a common class and reused. this would have a bigger impact on all test classes

# How could this be improved?

# Is this a feature you would work on yourself?

* [ ] I plan to open a pull request for this feature