Cairo - General contract type

[ericglau]

Part of #131.

Cairo equivalent of #112.

Only commits 223c384 and later need to be reviewed. The other commits are from #135, which this PR depends on.

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Adds a General contract type ("General" UI tab and general contract type for API):

• Pausable, Access Control, and Upgradeability sections.

Adds toggle for Access Control:

• Defaults to false.
• If certain features are selected that require access control, makes Access Control section required (checked and greyed out button) and defaults to ownable.
• Adds API function isAccessControlRequired for every contract type --> used for UI, and can be used by API consumers to determine in what cases would access control be required