Allow changing `SENTRY_SDK_NAME` at runtime

[marandaneto]

The build pipeline already considers the SENTRY_SDK_NAME config at compile time.
Ideally, the SDK is able to change its name at runtime.

sentry-native/include/sentry.h

Lines 26 to 32 in 903c17a

	#ifndef SENTRY_SDK_NAME
	# ifdef __ANDROID__
	# define SENTRY_SDK_NAME "sentry.native.android"
	# else
	# define SENTRY_SDK_NAME "sentry.native"
	# endif
	#endif

For example:
sentry_set_sdk_name(...) or sentry_options_set_sdk_name(...), some SDKs have it under the options while this attribute is internal/private but allow Hybrid SDKs to do it anyway.
Context getsentry/sentry-dart#1333