Small code modernizations (#835)

- Use std::numeric_limits<uid_t>::max() to ensure consistency with
  gui/gid
- Specify partition_id_t as a constexpr

Author: kheaactua

implementation/configuration/include/internal.hpp.in

@@ -190,7 +190,7 @@ enum class port_type_e {
 };
 
 using partition_id_t = std::uint8_t;
-const partition_id_t VSOMEIP_DEFAULT_PARTITION_ID = 0;
+inline constexpr partition_id_t VSOMEIP_DEFAULT_PARTITION_ID = 0;
 
 } // namespace vsomeip_v3
 

test/unit_tests/security_tests/ut_is_client_allowed.cpp

@@ -22,8 +22,8 @@ namespace {
 
     vsomeip_v3::gid_t invalid_uid = 1;
     vsomeip_v3::gid_t invalid_gid = 1;
-    vsomeip_v3::uid_t ANY_UID = 0xFFFFFFFF;
-    vsomeip_v3::gid_t ANY_GID = 0xFFFFFFFF;
+    vsomeip_v3::uid_t ANY_UID = std::numeric_limits<uid_t>::max();
+    vsomeip_v3::gid_t ANY_GID = std::numeric_limits<uid_t>::max();
 
     vsomeip_v3::gid_t deny_uid  = 9999;
     vsomeip_v3::gid_t deny_gid  = 9999;