ServiceArea: constructors with many args + assignment operator not making identical copy

[plauric]

Requesting changes: I would want some comments to actually be addressed instead of being argued as do not actually need to change (or if the argument of not changing is good, I would like to make sure I review the reply). After seeing the answers, I believe we need at least:

• use builders for arguments when the argument count starts being large (usually after around 4-5 arguments ... and always if there are same-type arguments especially bools or nullable things)
• do not use operator= to mean anything else than "exact copy"

Originally posted by @andy31415 in #33991 (review)

[andy31415]

As an offline discussion, it was discussed to make these as a separate PR instead of in #33991. I am ok with that as long as there is commitment for the followup to happen soon. Because historically we had a very low rate of actual promised followups, I would like to have a commitment that one of 2 things happen:

• followup PR(s) fix the above (great!)
• followups do not happen in 2-3 weeks, in which case Implementation of service area server #33991 and any followups on it would get rolled back (this should really not happen ... just having this as a guarantee that the followups have high priority)