(core) Remove code related to _grist_TableViews

Summary:
Removed some TS and python code interacting with this meta table. Not touching schema or migrations.

This is not really necessary, just checking my understanding and cleaning up in preparation for raw data views. I can also remove _grist_TabItems code while I'm at it.

Test Plan: this

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D3161

sandbox/grist/test_useractions.py

@@ -284,7 +284,7 @@ class TestUserActions(test_engine.EngineTestCase):
   #----------------------------------------------------------------------
 
   def init_views_sample(self):
-    # Add a new table and a view, to get some Views/Sections/Fields, and TableView/TabBar items.
+    # Add a new table and a view, to get some Views/Sections/Fields, and TabBar items.
     self.apply_user_action(['AddTable', 'Schools', [
       {'id': 'city', 'type': 'Text'},
       {'id': 'state', 'type': 'Text'},
@@ -361,11 +361,6 @@ class TestUserActions(test_engine.EngineTestCase):
         ]),
       ]),
     ])
-    self.assertTableData('_grist_TableViews', data=[
-      ["id",  "tableRef", "viewRef"],
-      [1,     1,          2],
-      [2,     1,          3],
-    ])
     self.assertTableData('_grist_TabBar', cols="subset", data=[
       ["id",  "viewRef"],
       [1,     1],
@@ -422,9 +417,6 @@ class TestUserActions(test_engine.EngineTestCase):
         ]),
       ]),
     ])
-    self.assertTableData('_grist_TableViews', data=[
-      ["id",  "tableRef", "viewRef"],
-    ])
     self.assertTableData('_grist_TabBar', cols="subset", data=[
       ["id",  "viewRef"],
       [1,     1],