feat: make vals able to eval dictionaries

[thomasbecker]

We've some use cases where we have plain dictionaries in yaml files and need to evaluate secret refs with vals. We've a workaround/hack to use yq to change this dictionaries into a format that vals likes and then back to it's origin after secrets are evaluated. But this is kinda hacky, thus this PR.

The yq hack (don't mind the extra quotings/escapes as this is part of a larger script):

 yq ". as \$in | {\"data\": \$in} | .data = (eval(.) | .data)" "$file" | vals eval | yq eval ".data" > "${file}.tmp" && mv "${file}.tmp" "$file"

[yxxhero]

@mumoshu WDYT?

[thomasbecker]

Any update on this one? It won't break anything and make vals work for plain dicts as well.

[mumoshu]

LGTM! Thank you very much for your contribution @thomasbecker!