Optimize PrettyNaming.IsOperator and prefix operator checks (#8715)
Optimize PrettyNaming.IsOperator and prefix operator checks (#8715)

* Optimize PrettyNaming.IsOperatorName

* Optimize IsValidPrefixOperatorUse, IsValidPrefixOperatorDefinitionName, IsPrefixOperator

* Cleanup

* More prefix op check optimization, remove duplication

* Fix index

* Cleanup

* Fix

* Review fixes
dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp,dsyme/fsharp