Xray should check for existing Issue Type names before creating its Issue Types

This improvement is to avoid Issue Type name clashing.

During installation, we should check if there are already other Issue Types with same name of the Xray ones.

If Xray does find an Issue Type with same name, it should apply some sort of prefix or suffix in the Xray Issue Type name.

Example:

Xray tries to install the Issue Type 'Test' but it finds the Jira instance already has one 'Test' issue type. So it renames the Xray 'Test' to 'Xray: Test' or 'xTest'.