[PSDK] Define maximum SSID length properly (reactos#7394)

Avoid using magic numbers for structures and ease the day for those
who do not remember IEEE 802.11 specifications by heart.

- Add a #define that matches by name with one used since day one
  of Visual Studio 2008 (VS2005 does not have Native Wi-Fi SDK)
- Remove magic constant from DOT11_SSID.ucSSID size definition

Reference: https://learn.microsoft.com/en-us/windows/win32/nativewifi/dot11-ssid
CORE-6905

Author: Vitaly Orekhov

sdk/include/psdk/windot11.h

@@ -64,7 +64,7 @@ typedef DOT11_MAC_ADDRESS* PDOT11_MAC_ADDRESS;
 
 typedef struct _DOT11_SSID {
     ULONG uSSIDLength;
-    UCHAR ucSSID[32];
+    UCHAR ucSSID[DOT11_SSID_MAX_LENGTH];
 } DOT11_SSID, *PDOT11_SSID;
 
 typedef struct _DOT11_BSSID_LIST {

sdk/include/psdk/wlantypes.h

@@ -7,6 +7,7 @@ typedef enum _DOT11_BSS_TYPE {
     dot11_BSS_type_any
 } DOT11_BSS_TYPE;
 
+#define DOT11_SSID_MAX_LENGTH 32
 
 #endif