lib: os: cbprintf: Add static packaging

[nordic-krch]

PR is based on #30675 but it extends it with support for creating packages statically. Statically means that a package (serialized string with arguments) is created as assignment to a buffer. Opposed to runtime package creation with cbprintf_package() (added by #30675) where string is analyzed and based on format specifiers a package is created.

In principle, CBPRINTF_STATIC_PACKAGE(buf, len, "test %d", n) resolves to assignments:

buf[0] = 0;
*(char **)&buf[1] = "test %d";
*(int *)&buf[5] = n;
len = 1 + sizeof(char *) + sizeof(int);

Added macros for:

• determining if static packaging can be done
  CBPRINTF_MUST_RUNTIME_PACKAGE returns 1 if runtime packaging must be used.
• determining size of the package
  In order to calculate length that can be assigned to const variable 2 step method is used. First part is creating local copies of arguments (handling sizeof("string") case). Second step macro returns package size:

CBPRINTF_STATIC_PACKAGE_SIZE_TOKEN(_tmp, "test %d", n);
static const size_t len = CBPRINTF_STATIC_PACKAGE_SIZE(_tmp, "test %d", n);

• creating a package
  Creating package on stack snippet:

CBPRINTF_STATIC_PACKAGE_SIZE_TOKEN(_tmp, fmt, ...);
static const size_t len = CBPRINTF_STATIC_PACKAGE_SIZE(_tmp, fmt, ...);
uint8_t buf[len];
CBPRINTF_STATIC_PACKAGE(buf, len, fmt, ...);

Extended test suite to compare static packaging against runtime whenever possible. Additionally, added 2 tests which validates macros behavior.

I have initial version of logger which is using this extension and supports basic functionality.

[nordic-krch]

Superseded by #32863.