Added detailed description to the C++ RM

[bmribler]

• Added c++ source files to file patterns to include detailed description of member functions.
• Cleaned up many outdated comments and added missing documentation of several parameters.
• Removed the C++ API main page for it's no longer relevant because the C++ documentation is now in the RM of the main library documentation.

Fixes #5529

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Important

Added C++ source files to FILE_PATTERNS in Doxyfile.in for detailed member function descriptions.

• Configuration:
  • Added @HDF5_CPP_SRC_DIR@/*.h and @HDF5_CPP_SRC_DIR@/*.cpp to FILE_PATTERNS in Doxyfile.in to include C++ source files for detailed member function descriptions.

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