refactor(utils): improve splitString using std::string_view input

[ZAINABKANGSIWALA]

Refactor the parameter type of splitString() in utils.cpp from 'const std::string&' to 'std::string_view' to avoid unnecessary string construction when called with string literals or string-like inputs.

Changes:

• utils.h: Declaration updated to use 'std::string_view'
• utils.cpp: Parameter changed from 'const std::string&' to 'std::string_view'
• utils.cpp: Updated 'std::string::size_type' to 'std::string_view::size_type'
• utils.cpp: Replaced 'push_back' with 'emplace_back'
• utils.cpp: Initialized 'pos2' with 'std::string_view::npos' to avoid uninitialized variable warning

Note:

• clangimport.cpp contains a separate static splitString() with a different signature; it is unrelated and unchanged.
• std::string_view is used only for input; ownership remains with the caller.

Call sites reviewed:

• errorlogger.cpp: passes std::string (implicit conversion)
• suppressions.cpp: passes std::string (implicit conversion)
• cppcheck.cpp: passes substr() result (implicit conversion)

No functional change in behavior.

[firewave]

Cppcheck targets C++11 so this doesn't work. If we move up to a newer standard it is very likely it will be done to C++14 first.

Also this is quite a pointless change unless you would also return views since you would still create copies. And the description which is unnecessarily multitudes bigger than the change is just baffling...