pinDropDown: make reserved and read only aware and disable if needed

AudioReactive: add disableROPins on WS, SCK, MCLK and SCL
4LD:  add disableROPins  on CLK

settingsum: 
- addfield: max 49 pins, if (global interface) also disabled, rename if to global, show 🔴 if pin claimed
- add disableROPins
- pinDropdownsPost
- rename SDA to if:SDA (etc) so it is part of claimed pins (also in set.cpp and xml.cpp)

xml.cpp:
- appendGPIOinfo(): get rsvd and ro_gpio from pinManager.isPinOk instead of hardcoded
- getSettingsJS: add pinDropdownsPost

usermods/usermod_v2_four_line_display_ALT/usermod_v2_four_line_display_ALT.h

@@ -1058,6 +1058,7 @@ class FourLineDisplayUsermod : public Usermod {
       bool isSPI = (type == SSD1306_SPI || type == SSD1306_SPI64);
       // WLEDMM add defaults
       oappend(SET_F("addInfo('4LineDisplay:pin[]',0,'','I2C/SPI CLK');"));
+      oappend(SET_F("disableROPins('4LineDisplay::pin[]',0);")); 
     #ifdef FLD_PIN_SCL
       oappend(SET_F("xOption('4LineDisplay:pin[]',0,' ⎌',")); oappendi(FLD_PIN_SCL); oappend(");"); 
     #endif