fix: update metadata function to use to_field with FieldMetadata::from

[BipulLamsal]

Which issue does this PR close?

• Closes Deprecate ExprSchemable::metadata #18930

What changes are included in this PR?

Deprecated 'ExprSchemable::metadata' method
Use to_field and convert the result with FieldMetadata::from

[martin-g]

I like the old API better.
But I am just a user! The DataFusion team has to decide.

[alamb]

I like the old API better. But I am just a user! The DataFusion team has to decide.

I agree this change makes the code harder to use

I wonder if there is some way to make FieldMetadata::from(expr) work (`impl From for &Field)?

I think the fact that to_field actually returns a (relation, field) makes using it akward

[alamb]

Thank you @BipulLamsal and @martin-g

[BipulLamsal]

I wonder if there is some way to make FieldMetadata::from(expr) work (`impl From for &Field)?

let me look this up