Update examples to use `module_load_output`

[lassemoldrup]

Task description

The smart contract examples should be updated so that any time they load the contract under test by manually entering the module output path (e.g. with module_load_v1), they should use module_load_output instead, which automatically gets the path. Note that this should only be done after the required functionality in cargo-concordium (Concordium/concordium-smart-contract-tools#167) is released.