feat: add external provider scaffold

[rsaz]

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PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Please describe the current behavior that you are modifying, or link to a relevant issue.

Issue Number: N/A

What is the new behavior?

Describe the new behavior or link to a relevant issue.

Add external provider scaffold command expressots add provider or expressots a provider

Does this PR introduce a breaking change?

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications below.

Other information

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