Automate account flag during compilation

[andrew-fleming]

This PR proposes to automatically include the --account_contract flag during compilation if the contract name ends with Account. If this is accepted, it:

• sets a precedent that account contracts should suffix their name with Account
  • includes the common Account.cairo
• solves the issue of compiling entire libraries such as OpenZeppelin's Contracts for Cairo
• will not trigger for contract names such as AccountManager.cairo
• can still be triggered for uncommon contract names manually
• sets the sole restriction that non-account contracts should not suffix their name with Account

This resolves #102.

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I think it'd be a good idea to add a directive (%) for account contracts as mentioned here by @JulissaDantes. This will probably have to be done in the StarkNet compiler.

[archseer]

Is this case sensitive? I've been using account.cairo/snake case names rather than camel case.

[martriay]

feel free to open a PR supporting it

[andrew-fleming]

Hey, @archseer! Yes, this is case sensitive for the automated flag, but you can still manually set it. Adding snake cased account might be a good idea :)