Reorganize order of accounts in instructions

[fedgiac]

(Inspired by this comment.)

The order of accounts in the instructions of this program is a bit inconsistent with what other Solana programs usually do.
For example, the token program tends to put sysvar accounts towards the end (but still before variable-size account input). Source: https://docs.rs/spl-token/latest/spl_token/instruction/enum.TokenInstruction.html

This issue is resolved if we come up with a reasonable ordering standard for instruction account and change the builders to stick to it.

[kaze-cow]

this would be a breaking change so we should accelerate this ticket in particular