The CMake module downloads `string-view-lite` from
https://github.com/martinmoene/string-view-lite
It is a single-file header-only version of C++17-like `string_view` for
C++98, C++03, C++11, and later.
Notices it also provides C++20 extensions like:
- empty()
- starts_with()
- ends_with()
- etc.
Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>