[fix] fix-filesystem-include-error

[luciouskami]

Description

fix-filesystem-include-error

#141

Motivation and Context

fs is a common acronym for filesystem namespaces that may be defined repeatedly across multiple header files,use aliases instead of explicitly declaring namespaces to avoid namespace redefinition error.

How Has This Been Tested?

before:

Error	C2757	'fs': a symbol with this name already exists and therefore this name cannot be used as a namespace name	
Error	C1907	unable to recover from previous error(s); stopping compilation

after:
build success.

Types of changes

• [✓] Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [✓] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.