*: drop strict_iecstrtoll(const char *str,..)

*: drop strict_iecstrtoll(const char *str,..)

replace strict_iecstrtoll(const char *str,..) with
strict_iecstrtoll(std::string_view, ..). which is more convenient.
and both of them share the same implementation:

strict_iec_cast<uint64_t>(str, err);

so they are interchangeable.

Signed-off-by: Kefu Chai <kchai@redhat.com>