[JIRA]: Create new issue has quite a few bugs with existing api calls

[jeremyfiel]

Describe the bug

i didn't go through every field but most of the fields I'm trying to use to query data in the Create New Issue UI are failing to return results.

assignee, linked issues has spotty behavior, custom fields (#23)

This is more of a generic issue to validate all of the Create New issue behavior with each endpoint being called. It seems the api surface has a lot of changes since this extension was created.

To Reproduce
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2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
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Environment and Version (please complete the following information):

• Atlassian Plugin Version (3.4.6)
• Visual Studio Code Version (x.x.x)
• Is this a local or cloud environment? (Cloud | Local)
• If Cloud, Browser (chrome, safari)
• If Local, OS (macOS, windows, linux)

Additional context
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[bwieger-atlassian-com]

@marcomura FYI for the upcoming project we are working on