examples: CFO program

[armaniferrante]

CFO program for the serum DEX and a bunch of misc features that make it easier to write.

New features include:

• #[account(address = <expr>)] constraint for checking an address is as specified.
• #[account(init, token = <mint-target>, authority = <auth-target>, ...)] constraint for creating token accounts inside an accounts context. This makes it a lot easier to check accounts are correct in susbequent instructions, since one can continue to use #[account(associated = ...)] (or seeds = <...>) to check the given account is correct.
• Anchor.toml [scripts] section added for running bash commands via anchor run <script-name>.
• Anchor.toml [clusters.<network>] table entries can now also use { address = <base58-str>, idl = <filepath-str> } to specify workspace programs.

[armaniferrante]

Going to checkpoint this work. Alhough the CFO program itself isn't complete, the features developed are immediately useful.

[fanatid]

• #[account(address = <expr>)] / #[account(init, token = <mint-target>, authority = <auth-target>, ...)] need updated docs in anchor-derive-accounts 😞
• Is [scripts] section really required? Scripts can be placed in package.json and run with npm run or Makefile...