[gl3w] Support to include GL extensions in header file (#38605)

Fix https://github.com/microsoft/vcpkg/issues/38588

Include the GL extension in the header file by adding the parameter
`--ext`.
Note: This method only adds GL extension and does not delete any
original method implementation.

Upstream： 
```
The generator script optionally takes the arguments:

--ext to include the GL Extensions in output header.
```
https://github.com/skaslev/gl3w?tab=readme-ov-file#options

- [x] Changes comply with the [maintainer
guide](https://github.com/microsoft/vcpkg-docs/blob/main/vcpkg/contributing/maintainer-guide.md).
- [ ] ~~SHA512s are updated for each updated download.~~
- [ ] ~~The "supports" clause reflects platforms that may be fixed by
this new version.~~
- [ ] ~~Any fixed [CI
baseline](https://github.com/microsoft/vcpkg/blob/master/scripts/ci.baseline.txt)
entries are removed from that file.~~
- [ ] ~~Any patches that are no longer applied are deleted from the
port's directory.~~
- [x] The version database is fixed by rerunning `./vcpkg x-add-version
--all` and committing the result.
- [x] Only one version is added to each modified port's versions file.

ports/gl3w/portfile.cmake

@@ -14,8 +14,12 @@ file(COPY "${CURRENT_INSTALLED_DIR}/include/KHR/khrplatform.h" DESTINATION "${SO
 
 vcpkg_find_acquire_program(PYTHON3)
 
+if("ext" IN_LIST FEATURES)
+    set(EXT "--ext")
+endif()
+
 vcpkg_execute_required_process(
-  COMMAND "${PYTHON3}" "${SOURCE_PATH}/gl3w_gen.py"
+  COMMAND "${PYTHON3}" "${SOURCE_PATH}/gl3w_gen.py" "${EXT}"
   WORKING_DIRECTORY "${SOURCE_PATH}"
   LOGNAME gl3w-gen
 )

ports/gl3w/vcpkg.json

@@ -1,7 +1,7 @@
 {
   "name": "gl3w",
   "version-date": "2018-05-31",
-  "port-version": 4,
+  "port-version": 5,
   "description": "Simple OpenGL core profile loading",
   "homepage": "https://github.com/skaslev/gl3w",
   "dependencies": [
@@ -15,5 +15,10 @@
       "name": "vcpkg-cmake-config",
       "host": true
     }
-  ]
+  ],
+  "features": {
+    "ext": {
+      "description": "include the GL Extensions in output header"
+    }
+  }
 }

versions/baseline.json

@@ -3042,7 +3042,7 @@
     },
     "gl3w": {
       "baseline": "2018-05-31",
-      "port-version": 4
+      "port-version": 5
     },
     "glad": {
       "baseline": "0.1.36",

versions/g-/gl3w.json

@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "a79b7a69f540bf9cd71464cabdfdd5cd67e72072",
+      "version-date": "2018-05-31",
+      "port-version": 5
+    },
     {
       "git-tree": "618626b6f1118dc2c80fa7bd2aae497c0d83b7c1",
       "version-date": "2018-05-31",