PY-85239: Add API to check if this welcome project is editable.

Junie and other features might change their behaviour depending on that API.
In GoLand, for example, Junie should not be available.
While in PyCharm the welcome screen project is like any other project.

See MTRH-1423.
so Junie can be used on that project.


(cherry picked from commit cf3f6c1a1812dbe12cc5db0e9bd4cbc8f3f84405)

IJ-MR-180671

GitOrigin-RevId: 31eafee7e49b86f985ca8a3a673363c445333a09

python/ide/impl/src/com/intellij/pycharm/community/ide/impl/welcomeScreen/PyCharmWelcomeScreenProjectProvider.kt

@@ -25,6 +25,10 @@ private class PyCharmWelcomeScreenProjectProvider : WelcomeScreenProjectProvider
     return project.name == MISC_PROJECT_WITH_WELCOME_NAME || project.name == MISC_PROJECT_NAME
   }
 
+  override fun doIsEditableProject(project: Project): Boolean {
+    return true
+  }
+
   override fun doIsForceDisabledFileColors(): Boolean = true
 
   override fun doGetCreateNewFileProjectPrefix(): String = "awesomeProject"