docs: update reported error text (#8533)

this matches more what is being reported. Especially the bit about `"mockedFunction"` is important, because otherwise it's a bit confusing what `mockName` will help with.

docs/MockFunctionAPI.md

@@ -188,10 +188,10 @@ expect(mockFn).toHaveBeenCalled();
 
 Will result in this error:
 
-```bash
-    expect(mockedFunction).toHaveBeenCalled()
+```
+expect(mockedFunction).toHaveBeenCalled()
 
-    Expected mock function to have been called.
+Expected mock function "mockedFunction" to have been called, but it was not called.
 ```
 
 ### `mockFn.mockReturnThis()`

website/versioned_docs/version-22.x/MockFunctionAPI.md

@@ -157,9 +157,9 @@ expect(mockFn).toHaveBeenCalled();
 Will result in this error:
 
 ```
-    expect(mockedFunction).toHaveBeenCalled()
+expect(mockedFunction).toHaveBeenCalled()
 
-    Expected mock function to have been called.
+Expected mock function "mockedFunction" to have been called, but it was not called.
 ```
 
 ### `mockFn.mockReturnThis()`

website/versioned_docs/version-23.x/MockFunctionAPI.md

@@ -183,10 +183,10 @@ expect(mockFn).toHaveBeenCalled();
 
 Will result in this error:
 
-```bash
-    expect(mockedFunction).toHaveBeenCalled()
+```
+expect(mockedFunction).toHaveBeenCalled()
 
-    Expected mock function to have been called.
+Expected mock function "mockedFunction" to have been called, but it was not called.
 ```
 
 ### `mockFn.mockReturnThis()`

website/versioned_docs/version-24.0/MockFunctionAPI.md

@@ -189,10 +189,10 @@ expect(mockFn).toHaveBeenCalled();
 
 Will result in this error:
 
-```bash
-    expect(mockedFunction).toHaveBeenCalled()
+```
+expect(mockedFunction).toHaveBeenCalled()
 
-    Expected mock function to have been called.
+Expected mock function "mockedFunction" to have been called, but it was not called.
 ```
 
 ### `mockFn.mockReturnThis()`