Run FppUtility in `cwd=context`


*Originating Project/Creator*
*Affected Component*
*Affected Architectures(s)*
*Related Issue(s)*
*Has Unit Tests (y/n)*
*Builds Without Errors (y/n)*
*Unit Tests Pass (y/n)*
*Documentation Included (y/n)*

Change Description

Running FppUtility.execute() in cwd=context. Necessary because fpp-to-cpp will output relative include paths based on CWD at runtime

Consider whether this behavior from fpp-to-cpp should be reworked.