Switch to using an aggregated logs query and infinite scrolling

This should allow users to work with large logs set.

Fixes #294

data/database.py

@@ -645,6 +645,9 @@ class LogEntry(BaseModel):
     indexes = (
       # create an index on repository and date
       (('repository', 'datetime'), False),
+
+      # create an index on repository, date and kind
+      (('repository', 'datetime', 'kind'), False),
     )