No return value of the `mbedtls` library functions is evaluated

[sorru94]

The HWID module and the UUID module use the mbedtls library but do not check the return value of any of its functions.

https://github.com/astarte-platform/astarte-device-sdk-esp32/blob/c790919f5a8e2a968f73ef2c48bcbcf32cbfe38d/src/astarte_hwid.c#L78-L83

https://github.com/astarte-platform/astarte-device-sdk-esp32/blob/c790919f5a8e2a968f73ef2c48bcbcf32cbfe38d/src/astarte_hwid.c#L94

https://github.com/astarte-platform/astarte-device-sdk-esp32/blob/c790919f5a8e2a968f73ef2c48bcbcf32cbfe38d/src/uuid.c#L88-L94

[sorru94]

The functions with ignored return values are:

• mbedtls_md_setup
• mbedtls_md_starts
• mbedtls_md_update
• mbedtls_md_finish
• mbedtls_base64_decode