Java API allow creating duplicate issue types

Issue Summary

Even though you can't create duplicate issue type with the same name through Jira UI or REST API, Jira still allows this through Java APIs.

Steps to Reproduce

1. Create an issue type called "Test"
2. Install Xray or Zephyr

Expected Results

Jira stops the creation of "Test" issuetype as it already exists

Actual Results

• Jira allows duplicate issuetype to be created
  
• Jira issue search with issuetype = "Test" will only show the issues of the lower issuetype ID

Workaround

Follow KB Jira issue search doesn't fetch all issues when there are duplicate issue types