feat: add Decision column to TUVote

In preparation for allowing TUs to change their votes on proposals,
we need a way to track what users vote for.

Without this, the vote decisions are stored within the related
TU_VoteInfo record, decoupled from the user who made the vote.

That being the case meant we cannot actually change a vote, because
we can't figure out what TU_VoteInfo decision columns to decrement
when the vote has changed.

You may be wondering why we aren't removing the decision columns out
of TU_VoteInfo with the advent of this new column. The reason being:
previous votes are all calculated off of the TU_VoteInfo columns, so
without a manual DB rework, relocating them to the user-related vote
records would break outcomes of old proposals. So, the plan is:
we'll solely use this column for votes from this point on to track
what decision a user made internally, which will open up TUs changing
their decision.

In addition, this migration resets all running proposals:
- all votes are deleted
- time is reset to Start when migration is run

This was necessary to put running proposals into a state that can
take advantage of the new revote system.

Signed-off-by: Kevin Morris <kevr@0cost.org>

test/test_tu_vote.py

@@ -4,7 +4,7 @@ from sqlalchemy.exc import IntegrityError
 
 from aurweb import db, time
 from aurweb.models.account_type import TRUSTED_USER_ID
-from aurweb.models.tu_vote import TUVote
+from aurweb.models.tu_vote import YES_ID, TUVote
 from aurweb.models.tu_voteinfo import TUVoteInfo
 from aurweb.models.user import User
 
@@ -36,10 +36,12 @@ def tu_voteinfo(user: User) -> TUVoteInfo:
 
 def test_tu_vote_creation(user: User, tu_voteinfo: TUVoteInfo):
     with db.begin():
-        tu_vote = db.create(TUVote, User=user, VoteInfo=tu_voteinfo)
+        tu_vote = db.create(TUVote, User=user, VoteInfo=tu_voteinfo,
+                            Decision=YES_ID)
 
     assert tu_vote.VoteInfo == tu_voteinfo
     assert tu_vote.User == user
+    assert tu_vote.Decision == YES_ID
     assert tu_vote in user.tu_votes
     assert tu_vote in tu_voteinfo.tu_votes
 
@@ -52,3 +54,12 @@ def test_tu_vote_null_user_raises_exception(tu_voteinfo: TUVoteInfo):
 def test_tu_vote_null_voteinfo_raises_exception(user: User):
     with pytest.raises(IntegrityError):
         TUVote(User=user)
+
+
+def test_tu_vote_bad_decision_raises_exception(user: User,
+                                               tu_voteinfo: TUVoteInfo):
+    with pytest.raises(IntegrityError):
+        TUVote(User=user, VoteInfo=tu_voteinfo, Decision=None)
+
+    with pytest.raises(IntegrityError):
+        TUVote(User=user, VoteInfo=tu_voteinfo, Decision=0)