Simplify Constructor Options

[peterstace]

There are currently 2 constructor options:

• Disable All Validations
• Disable Expensive Validations

The logic for working out which validations to perform can get a bit tricky... And the semantics around what an "expensive" validation also feels fuzzy.

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Steps to implement this ticket:

• Remove the DisableExpensiveValidations constructor option.
• Remove the skipExpensiveValidations field of the ctorOptionSet type.
• Remove the doExpensiveValidations and doCheapValidations methods on the ctorOptionSet type.
• For each concrete geometry, skip all validation steps by checking the skipAllValidations flag on the ctorOptionSet struct (maybe rename the flag to skipValidations).