Add OmicsUri region, account_id, and default file_name support

[ahenroid]

Issue #, if available: N/A

Description of changes:

• Parse region and account ID segments of the URI and add corresponding attributes to OmicsUri
• Allow URIs with no file_name segment, adding in the default file, SOURCE1 for a ReadSet or SOURCE for a Reference
• Tighten URI parsing by using a regular expression
• Extend and add unit tests to bring URI parser coverage to 100%

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[ahenroid]

I've updated this PR with the reviewer recommendation to validate & parse URIs with a regular expression