Freeze readonly fields

[eileenmcnaughton]

alternate to #20197

[civibot]

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[colemanw]

@eileenmcnaughton as a follow-up (not a blocker) I think we should add readonly to the APIv4 output. Would it make more sense on get or getFields? And how should set be handled in the case of readonly?

[demeritcowboy]

Thanks @eileenmcnaughton this works for me and also still satisfies formRules etc.

@pradpnayak if you can confirm this also works for you then I think it's mergeable.

The @todo comment isn't necessary anymore in the trait, but that's minor.

[eileenmcnaughton]

@colemanw I guess it could work on getfields - it's just a getMandatory() look up when compiling

[colemanw]

Ok @eileenmcnaughton I added it to #20191

[demeritcowboy]

@pradpnayak does this fix the problem with the logging setting for you? I think it's good to merge.

[pradpnayak]

Yes it does,

thanks @eileenmcnaughton and @demeritcowboy