Fix invalid string cast

[GiantBlargg]

In PR #51908 these lines were added:

godot/modules/text_server_adv/text_server_adv.cpp

Line 1234 in f3ab094

ERR_FAIL_COND_V_MSG(error != 0, false, TTR("FreeType: Error initializing library:") + " '" + String(FT_Error_String(error)) + "'.");

godot/modules/text_server_adv/text_server_adv.cpp

Line 1252 in f3ab094

ERR_FAIL_V_MSG(false, TTR("FreeType: Error loading font:") + " '" + String(FT_Error_String(error)) + "'.");

While this compiles when tools=yes, when tools=no it produces a compile error.

./core/string/ustring.h:526:22: error: invalid cast to function type 'String()'
  526 | #define TTR(m_value) (String())
./core/error/error_macros.h:94:26: note: in definition of macro 'DEBUG_STR'
   94 | #define DEBUG_STR(m_msg) m_msg
      |                          ^~~~~
modules/text_server_adv/text_server_adv.cpp:1234:25: note: in expansion of macro 'ERR_FAIL_COND_V_MSG'
 1234 |                         ERR_FAIL_COND_V_MSG(error != 0, false, TTR("FreeType: Error initializing library:") + " '" + String(FT_Error_String(error)) + "'.");
      |                         ^~~~~~~~~~~~~~~~~~~
modules/text_server_adv/text_server_adv.cpp:1234:64: note: in expansion of macro 'TTR'
 1234 |                         ERR_FAIL_COND_V_MSG(error != 0, false, TTR("FreeType: Error initializing library:") + " '" + String(FT_Error_String(error)) + "'.");
      |                                                                ^~~
./core/string/ustring.h:526:22: error: invalid cast to function type 'String()'
  526 | #define TTR(m_value) (String())
./core/error/error_macros.h:94:26: note: in definition of macro 'DEBUG_STR'
   94 | #define DEBUG_STR(m_msg) m_msg
      |                          ^~~~~
modules/text_server_adv/text_server_adv.cpp:1252:25: note: in expansion of macro 'ERR_FAIL_V_MSG'
 1252 |                         ERR_FAIL_V_MSG(false, TTR("FreeType: Error loading font:") + " '" + String(FT_Error_String(error)) + "'.");
      |                         ^~~~~~~~~~~~~~
modules/text_server_adv/text_server_adv.cpp:1252:47: note: in expansion of macro 'TTR'
 1252 |                         ERR_FAIL_V_MSG(false, TTR("FreeType: Error loading font:") + " '" + String(FT_Error_String(error)) + "'.");
      |                                               ^~~

A similar problem is also present in text_server_fb, but is disabled by default.

This PR alters the tools=no stubs of TTR and other Tool Translate functions to allow compiling again.

[Faless]

To be honest, I was a bit surprised this got interpreted as a cast, so, great work 👍 🥇 !