[FEATURE REQ] CreateIfNotExists/DeleteIfExists/Exists for File

[amnguye]

Is your feature request related to a problem? Please describe.
Related to issue #7211
In the old API there are 'convenience' methods like CreateIfNotExists/DeleteIfExists for File and FileShare

Describe the solution you'd like
Helper methods (like CreateIfNotExists/DeleteIfExists) for Files

Describe alternatives you've considered
Can easily be worked around. Refer to #7211.

Additional context
Add any other context or screenshots about the feature request here.

Information Checklist
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• Expected solution specified

[seanmcc-msft]

In track 1, we have:

• CloudFileShare.CreateIfExists(), .DeleteIfExists(), and .Exists()
• CloudDirectoryClient.CreateIfExists(), .DeleteIfExists(), and .Exists()
• CloudFileClient.DeleteIfExists(), .Exists(). I think we should also add CreateIfNoExists()

[seanmcc-msft]

Resolved with #10074