[io] Refactor IOStream to use an external printf implementation

[salkinium]

Our printf implementation was good for many years, however, a lot of features were missing and our tests, while helpful, weren't complete.
In addition I wanted to refactor IOStream for a long time now, and add some feature options for the AVRs to selectively enable long long, float, ptrdiff and printf-style formatting.

This completely replaces all formatting code with mpaland/printf, and cleans up the IOStream class, with only these changes to the behavior:

• %p does not print the leading 0x anymore, you have to add it yourself.
• printing bools in binary mode only prints 0 or 1 not the leading 7 zeros anymore. stream << modm::bin << (bool)1 prints 1, not 00000001.
• passing a const char * array will always print in ascii mode. stream << modm::hex << "Hallo" prints Hallo, not 48616C6C6F00.
• For AVRs any options for %f, %e or %g are ignored and the value is output in scientific notation.

Ran unittests on:

• hosted-darwin
• STM32
• AVR

cc @se-bi @rleh @chris-durand @strongly-typed

[salkinium]

I was concerned about AVR code size, so I did a regression test and for using the streaming interface it looks pretty much the same, but printf on the other hand has gotten bigger when compiled with long long support and floating point support. I think this is fine, since the new printf contains a lot better formatting support, so this increase is acceptable.

AVR Baseline:

#include <modm/platform.hpp>
#include <modm/io.hpp>

using LoggerDevice = modm::IODeviceWrapper< modm::platform::Uart0, modm::IOBuffer::BlockIfFull >;
LoggerDevice loggerDevice;
modm::IOStream ostream(loggerDevice);

int
main()
{
	// test code
}

840 bytes

Output stream only:

{{type}} value = 0;
ostream << value;

type	before	after	:io:with_long_long	:io:with_float
bool	1130	1196
char	1030	1026
uint8_t	1172	1176
int16_t	1246	1216
uint16_t	1188	1192
int32_t	1284	1244
uint32_t	1256	1216
int64_t	n/a	2682	x
uint64_t	n/a	2542	x
float	2350	2526		x
double	2350	2526		x
ostream	1808	1756
ostream	n/a	3662	x
ostream	3342	3344		x
ostream	n/a	5248	x	x

printf only:

{{type}} value = 0;
ostream.printf("%{{type}}", value);;

type	before	after	:io:with_long_long	:io:with_float
printf	3522	3390
printf	n/a	4636	x
printf	3522	5074		x
printf	n/a	6302	x	x