Support paging of merge candidate list

[mpeels]

Notes

1. Updates response from merge list API to include paging information
2. Updates merge controller to have base path of /merge

JIRA

• Related story: CND-242

Checklist

• PR focuses on a single story.
• New unit tests added and ensured they pass.
• Service has been tested in local and it works as expected.
• Documentation has been updated for this code change (if needed).
• Code follows the Java Coding Conventions (https://www.oracle.com/java/technologies/javase/codeconventions-programmingpractices.html).

Types of changes

What types of changes does this PR introduces?

• Bugfix
• New feature
• Breaking change

Testing

• Does this PR has >90% code coverage?
• Is the screenshot attached for code coverage?
• Does the gradle build pass in your local?
• Is the gradle build logs attached?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
92.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[snehaasjournal]

Everything looks good. 🥇

My only nit-pick suggestion would be to DRY up the methods markMergedRecordAsMerge, markNonActiveRecordAsNoMerge, and markSingleRemainingRecordAsNoMergeIfExists in updateMergeStatusForPatients() in MergeGroupHandler.java since I see they all call DB updates with overlapping parameters. Not a blocker and it's not a part of this PR.