Review Code suggestions

[prupipho]

• Move MakeSafeProjectName in CoreTemplateStudio.Core and CoreTemplateStudio.Core to a more accurate folder and remove duplication.
• Make fields readonly
• Simplify interpolations
• Use pattern matching
• Do not use Count when Any can be used
• Use Count/Length property instead of Count()
• Simplify conditional expressions
• Remove unnecessary suppressions
• Remove unnecessary assignments
• Simplify object initializations
• 'using' statement can be simplified
• Redundant and unnecesary assignments
• Remove unused methods
• Remove unused function parameters
• Remove not access fields
• Remove unused directives