docs(weaver/samples): pin solc to v0.8.8 and turn off IR for Besu asset exchange

[petermetz]

1. Without having it pinned to v0.8.8, some breaking changes that solc
   has snuck in [1] [2] around v0.8.15 (for IR) are breaking the contract
   deployment in a way that opcodes end up in the migration contract's
   constructor that Besu does not recognize ("opcode INVALID" in the besu
   logs if you set the log level to "ALL") in the Besu logs and then sends
   back an "internal error" message via the JSON-RPC response, which is a
   bug IMO it should state that the user input was invalid (user input
   being the contract)
2. Disabled IR in the truffle (solc) config which is a step backwards
   because it's a new feature of the solidity compiler that has certain
   benefits to it compared to the legacy compilation mode, but enabling it
   breaks the build so it just had to be done. In the future if someone
   has time to do a deep dive on why exactly it's failing, then it should
   be re-enabled because having the legacy compilation mode being our default
   is technical debt that should be paid off rather sooner than later because
   we never know how it will come back to cause different issues later on.

When IR is enabled, the following error occurs (even on the pinned v0.8.8 solc):

Compiling ./contracts/transferInterface.sol
YulException: Variable var_amount_3290 is 9 slot(s) too deep inside the stack.

[1] https://docs.soliditylang.org/en/v0.8.15/ir-breaking-changes.html#semantic-only-changes
[2] ethereum/solidity#13311 (comment)

Fixes #2423

Signed-off-by: Peter Somogyvari [email protected]

[izuru0]

LGTM