Incorrect order in `find_package` in `alt_classifier` package's CMakeLists.txt

[harshsinh]

Documentation of find_package says

A package-specific list of required components may be listed after the COMPONENTS option (or after the REQUIRED option if present). Additional optional components may be listed after OPTIONAL_COMPONENTS. Available components and their influence on whether a package is considered to be found are defined by the target package.

Consequently this package would show OpenCV not found on compilation.