Add some APIs to make it more convenient for users to construct InvokeHostFunction.

[overcat]

What problem does your feature solve?

Currently, users need to construct InvokeHostFunction directly. I want to add some interfaces to help users quickly construct operations such as calling contracts and creating contracts.

What would you like to see?

Add the following interfaces.

• upload_contract_wasm
• create_contract
• deploy_create_token_contract_from_asset
• deploy_create_token_contract_from_address
• invoke_contract_function

What alternatives are there?

None

Estimated working hours: 8

[sreuland]

this is great coverage, it might be worthwhile to split the functions up into sub-tickets if you prefer. for 'invoke_contract_function`, could use the js sdk's Contract.call() as a reference.

[overcat]

Implemented in #497.