Add bumplock to post modify form, and add set_bump permission

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/forms.py

@@ -127,7 +127,7 @@ class PostModifyForm(ModelForm):
         model = Post
         # we specify fields up here too because otherwise they won't be
         # recognized by the form to update values
-        fields: list[str] = ["sticky"]
+        fields = ["sticky", "bump"]
 
     def __init__(self, *args, user, **kwargs):
         super(PostModifyForm, self).__init__(*args, **kwargs)
@@ -135,6 +135,8 @@ class PostModifyForm(ModelForm):
         fields = []
         if self.user.has_perm("board.set_sticky"):
             fields += ["sticky"]
+        if self.user.has_perm("board.set_bump"):
+            fields += ["bump"]
         # NOTE:
         # We do *not* need to check permissions against these fields we're
         # setting down here in the self.clean() function in the case that a