individual unsafe blocks

driveby resolve clippy lint

add `Modem` as a device class to query for COM ports

some refactoring of `get_ports_guids` to handle multiple class names

clarifying comment

filter to COM ports rather than removing LPT (unknown what else modems could show up as)

raw ports only need to be iterated if additional ports have been found

resolve typo in comment

str -> w_string function

critique the moethod later...

`get_ports_guids` using `_W` win32 API

`PortDevices::new()` using `_W` win32 API

`PortDevices::instance_id()` using `_W` win32 API

`PortDevices::name()` using `as_utf16`

add utf16->utf8 function

handles the conversion and null trimming

use `from_utf16_lossy_trimmed`

`PortDevice::property()` handling a larger than expected property by retrying

`get_registry_com_ports` using utf16 API

also removed all the unused optional parameters from `RegQueryInfoKey`

minor cleanup

Let's use the same type names, variable names, and the same checks for
easily comparing them.

There is neither an explanation in the code nor does the history of this
check reveal any insight in why it should be present. If the buffer is
too small, what are we getting then, truncated data? I don't see the
point in processing this data.

Let's check it the same way as for other registry data.

Harmonize the buffer sizes used here. If we are already in the mood for
spending 100 characters, MAX_PATH won't hurt either.

Co-authored-by: Christopher Smyth <[email protected]>