Creating Jira issues fails when the issue type has mandatory fields

[fniessink]

Describe the bug Creating Jira issues fails when the issue type has mandatory fields

To Reproduce Steps to reproduce the behaviour:

1. Add a Jira issue tracker and select an issue type that has one or more mandatory fields
2. Create an issue from Quality-time
3. See the toaster message: "Could not create issue / 405 Client Error: for url: https://jira.example.org/rest/api/2/issue"

Expected behaviour

• Don't allow the user to pick an issue type with mandatory fields when configuring the issue tracker.
• Do show the issue types with mandatory fields in the drop down, but greyed out and with a subheader saying "This issue type cannot be used because it has mandatory fields"
• Use the Jira issue metadata endpoint to check for mandatory fields (see https://developer.atlassian.com/server/jira/platform/jira-rest-api-example-discovering-meta-data-for-creating-issues-6291669/).
• When the user clicks "Create new issue", check for mandatory fields and if the issue type has mandatory fields, give feedback via the toaster: "Could not create issue / The issue type has mandatory fields. Please select an issue type without mandatory fields in the issue tracker configuration" and set the issue type in the issue tracker config to None.

Your environment (please complete the following information):

• Quality-time version v5.15.0.