Fix: PascalCaseNamingConvention splits consecutive uppercase acronyms (AutoMapper #4593 backport)

[gthen95]

Description

This PR backports a fix from AutoMapper (#4593) to address an issue where PascalCaseNamingConvention incorrectly splits consecutive uppercase letters (acronyms).

The Issue:
When mapping properties containing acronyms like FormXML, the Split method previously separated every single uppercase letter (Form, X, M, L), causing the mapping convention to fail to match the properties.

The Fix:
Updated the splitting condition to verify if the current uppercase letter is surrounded by other uppercase letters. It now correctly identifies acronyms and keeps them intact (e.g., FormXML correctly splits into Form and XML).

References:

• Original AutoMapper Fix: PascalCaseNamingConvention is splitting "FormXML" to "Form" "X" "M" "L" LuckyPennySoftware/AutoMapper#4593