Fully qualify the sodium_*() function calls

This avoids a lookup to see if the functions exist in the
`ParagonIE\ConstantTime` namespace and ensures that there is no “userland” fake
implementation taking precedence.

Author: TimWolla

src/Base64.php

@@ -61,7 +61,7 @@ public static function encode(
             };
             if ($variant > 0) {
                 try {
-                    return sodium_bin2base64($binString, $variant);
+                    return \sodium_bin2base64($binString, $variant);
                 } catch (SodiumException $ex) {
                     throw new RangeException($ex->getMessage(), $ex->getCode(), $ex);
                 }
@@ -93,7 +93,7 @@ public static function encodeUnpadded(
             };
             if ($variant > 0) {
                 try {
-                    return sodium_bin2base64($src, $variant);
+                    return \sodium_bin2base64($src, $variant);
                 } catch (SodiumException $ex) {
                     throw new RangeException($ex->getMessage(), $ex->getCode(), $ex);
                 }
@@ -207,7 +207,7 @@ public static function decode(
                 };
                 if ($variant > 0) {
                     try {
-                        return sodium_base642bin($encodedString, $variant);
+                        return \sodium_base642bin($encodedString, $variant);
                     } catch (SodiumException $ex) {
                         throw new RangeException($ex->getMessage(), $ex->getCode(), $ex);
                     }

src/Hex.php

@@ -50,7 +50,7 @@ public static function encode(
     ): string {
         if (\extension_loaded('sodium')) {
             try {
-                return sodium_bin2hex($binString);
+                return \sodium_bin2hex($binString);
             } catch (SodiumException $ex) {
                 throw new RangeException($ex->getMessage(), $ex->getCode(), $ex);
             }
@@ -119,7 +119,7 @@ public static function decode(
     ): string {
         if (\extension_loaded('sodium') && $strictPadding) {
             try {
-                return sodium_hex2bin($encodedString);
+                return \sodium_hex2bin($encodedString);
             } catch (SodiumException $ex) {
                 throw new RangeException($ex->getMessage(), $ex->getCode(), $ex);
             }