Simplify actions block expressiveness as specification

[samuelmanzanera]

Is your feature request related to a problem?

Currently smart contract actions block are defined by direct code. However since the AEIP16 we introduce a way to simplify it for someone whising to use a more specification format as an extension of the existing condition keyword list.

Describe the solution you'd like

So we can support a new syntax for the actions block to use a keyword list as return to the actions block, as defined in:

actions triggered_by: transaction, on: upgrade, as: [
    code: transaction.content
]

actions triggered_by: transaction as: [
    content: "Hola"
]

Additional context

No response

Epic

No response