Feature request: define more specific types for decorators

[dreamorosi]

Description of the feature request

As discussed internally, we need to define more specific types for the method decorator that currently uses the any type:

// TODO: Revisit type below & make it more specific
// eslint-disable-next-line  @typescript-eslint/no-explicit-any
type MethodDecorator = (target: any, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<any>) => any;

Related issues, RFCs

#107

[dreamorosi]

This issue requires further investigation and depending on the outcome, the current type might end up staying.

The new potential type should be able to accept any sync or async function. If this is not possible, we should document the reasoning here and remove the #TODO from the code.

If anyone is interested in picking this up, please leave a comment here, then discuss your findings and proposed changes before opening a PR.