Ability to natively deal with types derived from go scalar types

[alvaroaleman]

Change
Summary of the proposed change and some details about what problem
it helps solve.

I have a custom string type downstream (type myType string) and currently I have to write a CustomTypeAdapter that casts this to string to be able to use it. It would be great if the DefaultTypeAdapter could do this by itself, having to write a CustomTypeAdapter is needlessly complicated IMHO.

Example
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Alternatives considered
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