Add the ability to call exposed struct methods on realm variables

[gfanton]

Description

It would be beneficial to have the ability to call exposed struct methods on realm variables. This enhancement could be particularly useful for larger realms looking to better organize and categorize their code. Coupled with indexing on the helper page (as shown here), we could come closer to adopting a documentation style similar to that of Golang.

[moul]

Absolutely loving it!

We can already call exposed struct methods by making a new contract:

import "gno.land/r/realmfoo"

func Bar() {
    realmfoo.Baz.Lorem()
}

I'm thinking of enhancing gnokey maketx call to support dots in endpoints: gnokey maketx call -pkgaddr gno.land/r/realmfoo -method Baz.Lorem.

I'm also keen on grouped struct methods in generated documentation. It'll help with a structured approach for admin tasks, making it less noisy for newcomers.

Just a heads up, I'm working indirectly on this in #1001. If it gets accepted, it'll cover a small part of your proposal.

[moul]

Btw, could be cool to use a single arg like gno.land/r/realmfoo.Baz.Lorem instead of -pkgaddr and -method.

Maybe for the #1017.

[moul]

Regarding issue #1042, it's essential to establish secure best practices and design patterns.

For calls such as gno.land/r/realmfoo.Baz.Lorem, we might prefer using func Baz() bazInstance { return baz } over the simpler var Baz bazInstance.
This approach warrants further examination. Afterward, we can either utilize a linter or restrict the VM from exposing structures directly.

By integrating solutions like Gnoffee (#1092), we aim to maintain code readability while enhancing security.