Undo some TODO (#3024)

* TODO FL-3497: impossible to fix with current memory allocator

* TODO FL-3497: removed, requires radically different settings approach

* TODO FL-3514: removed, yes we should

* TODO FL-3498: implemented, guarding view port access with mutex.

* TODO FL-3515: removed, questionable but ok

* TODO FL-3510: removed, comment added

* TODO FL-3500: refactored, store pin numbers in GpioPinRecord, fix gpio app crash caused by incorrect gpio_pins traversal.

* Format Sources

* TODO FL-3505: removed, mutex alone is not going to fix issue with WPAN architecture

* TODO FL-3506: removed, change ownership by copy is good

* TODO FL-3519: documentation and link to source added

* Lib: remove unneded total sum from comment in bq27220

---------

Co-authored-by: hedger <hedger@users.noreply.github.com>

firmware/targets/f7/ble_glue/ble_glue.c

@@ -222,7 +222,6 @@ bool ble_glue_wait_for_c2_start(int32_t timeout) {
     bool started = false;
 
     do {
-        // TODO FL-3505: use mutex?
         started = ble_glue->status == BleGlueStatusC2Started;
         if(!started) {
             timeout--;

firmware/targets/f7/ble_glue/services/gatt_char.c

@@ -14,7 +14,6 @@ void flipper_gatt_characteristic_init(
     furi_assert(char_instance);
 
     // Copy the descriptor to the instance, since it may point to stack memory
-    // TODO FL-3506: only copy if really comes from stack
     char_instance->characteristic = malloc(sizeof(FlipperGattCharacteristicParams));
     memcpy(
         (void*)char_instance->characteristic,