Fix Warnings (#1744)

* Remove -w (Suppress all warnings, including those which GNU CPP issues by default.) and add back in -Wall (Turn on all optional warnings which are desirable for normal code.) from build_flags

* Fixes warning: suggest parentheses around '+' in operand of '&' [-Wparentheses]

* Fixes warning: "CONFIG_LITTLEFS_FOR_IDF_3_2" redefined

* Fixes warning: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'uint64_t {aka long long unsigned int}' [-Wformat=]

* Fixes warning: enumeration value 'onoff' not handled in switch [-Wswitch]

* Fixes warning: "ntohl" redefined, warning: "ntohs" redefined, warning: "htonl" redefined, warning: "htons" redefined
- Original fix: 858f8f4ee9

* Fixes warning: unused variable 'mainSeg' [-Wunused-variable]

* Fixes warning: unused variable 'start' [-Wunused-variable]

* (untested!) Fixes warning: operation on '...' may be undefined [-Wsequence-point]

* Fixes warning: unused variable

* Fixes warning: unused variable and warning: narrowing conversion

* Fixes warning: unused variable

* Fixes warning: unused variable

* (untested!) Fixes warning: statement has no effect [-Wunused-value]

* Fixes warning: control reaches end of non-void function

* Fixes warning: unused variable

* Fixes warning: left operand of comma operator has no effect

* Fixes warning: no return statement in function returning non-void

* (untested!) Fixes warning: ISO C++ forbids converting a string constant to 'char*' and fixes warning: unused variable 'nPins'

* Fixes warning: deleting array 'dmxData'

* Fixes warning: unused variable

* Remove all warning suppression buildflags

Co-authored-by: Louis Beaudoin <louis@embedded-creations.com>
Co-authored-by: Aircoookie <dev.aircoookie@gmail.com>

wled00/um_manager.cpp

@@ -32,6 +32,7 @@ bool UsermodManager::add(Usermod* um)
   if (numMods >= WLED_MAX_USERMODS || um == nullptr) return false;
   ums[numMods] = um;
   numMods++;
+  return true;
 }
 
 byte UsermodManager::getModCount() {return numMods;}