Some versions of clang 14 (macOS+android) don't implement
`string_view(It first, It last)`, so let's use
`string_view(const CharT*, size_type)` instead.
Also remove unused header leftover from old code that uses std::string.
Since the HIO request is basically treated like a syscall, we need to
stop emulation while waiting for the GDB client to reply with the
result. This ensures any memory queries etc. that GDB makes to fulfill
the HIO request are accessing memory as it was at the time of the
request, instead of afterwards.
This also does kind of a hacky way of sending HIO requests, since we
don't have a direct way of signaling a request should be sent like the
Rosalina implementation.
To improve this, it could probably do some kind of signal sending which
the main run loop handles instead of GDBStub::HandlePacket();
