FORM type embed doesn't support a default

[mdroidian]

It should support block refs and arbitrary text

steps to repo

- #SmartBlock bugEmbedDefault
    - <%SET:default,<%RESOLVEBLOCKREF:Here's some default content for our form inputs%>%><%NOBLOCKOUTPUT%>
    - <%SET:defaultForm,<%FORM:formEmbedDefault%>%>
- #SmartBlock bugEmbedDefaultRef
    - <%SET:default,((9DkhqxK3x))%><%NOBLOCKOUTPUT%>
    - <%SET:defaultForm,<%FORM:formEmbedDefault%>%>
- formEmbedDefault
    - fields
        - embed-input
            - type
                - embed
            - label
                - Embed field example (default does not work)
            - default
                - <%GET:default%>
    - output
        - variables
    - submit
        - Submit
    - cancel
        - Cancel

Reported by Chris H. via slack