modernize-use-starts-ends-with

Checks for common roundabout ways to express starts_with and ends_with and suggests replacing with the simpler method when it is available. Notably, this will work with std::string and std::string_view.

Covered scenarios:

Expression	Replacement
u.find(v) == 0	u.starts_with(v)
u.rfind(v, 0) != 0	!u.starts_with(v)
u.compare(0, v.size(), v) == 0	u.starts_with(v)
u.substr(0, v.size()) == v	u.starts_with(v)
v != u.substr(0, v.size())	!u.starts_with(v)
u.compare(u.size() - v.size(), v.size(), v) == 0	u.ends_with(v)
u.rfind(v) == u.size() - v.size()	u.ends_with(v)