true-fantom/math: Add "sign" block (#1981)

continuation of #1980,
everything from there applies except:

- ctrl + f replace every time I said "normalize" with "sign of"
- block code was changed a bit because apparently there's a math
function to get sign (how am i just now learning of this)


![chrome_uiOoLW48ex](https://github.com/user-attachments/assets/b880379d-8a5d-4848-b84f-69948ee2500a)

---------

Co-authored-by: DangoCat[bot] <[email protected]>

Author: NexusKitten

extensions/true-fantom/math.js

@@ -384,6 +384,18 @@
             extensions: ["colours_operators"],
           },
           "---",
+          {
+            opcode: "sign_of",
+            blockType: Scratch.BlockType.REPORTER,
+            text: Scratch.translate("sign of [A]"),
+            arguments: {
+              A: {
+                type: Scratch.ArgumentType.NUMBER,
+                defaultValue: 0.1,
+              },
+            },
+            extensions: ["colours_operators"],
+          },
           {
             opcode: "clamp_block",
             blockType: Scratch.BlockType.REPORTER,
@@ -646,6 +658,9 @@
     exactly_cont_block({ A, B }) {
       return cast.toString(A).includes(cast.toString(B));
     }
+    sign_of({ A }) {
+      return Math.sign(cast.toNumber(A));
+    }
     clamp_block({ A, B, C }) {
       if (cast.compare(A, B) < 0) {
         return B;