Add previewnet deployment details

[sisyphusSmiling]

Closes: #9

Description

Adds Previewnet deployment details to flow.json along with supporting templates & deployment args. Previewnet deployment currently only supports onboarding. Once EVM contract updates are reviewed (relevant PR: onflow/flow-go#5677), merged and changes updated on PN, bridge functionality will be enabled end-to-end through the COA resource.

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For contributor use:

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the standards mentioned here.
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.82%. Comparing base (428634e) to head (a820914).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #37      +/-   ##
==========================================
- Coverage   82.88%   82.82%   -0.06%     
==========================================
  Files          18       19       +1     
  Lines         818      827       +9     
==========================================
+ Hits          678      685       +7     
- Misses        140      142       +2     

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