[db] fixes for context_node_ngrams_view materialized view

Unique index is necessary when one wants to refresh the view
concurrently.
4 jobs for 199-dev-materialized-view-refresh-issue in 71 minutes and 42 seconds (queued for 4 minutes and 2 seconds)
Status Job ID Name Coverage
  Deps
passed #7230
deps

00:16:29

 
  Test
passed #7231
test

00:23:44

 
  Docs
passed #7232
allowed to fail
docs

00:28:10

 
  Cabal
failed #7233
allowed to fail
cabal

00:03:17

 
Name Stage Failure
failed
cabal Cabal
cabal: Could not resolve dependencies:
[__0] trying: gargantext-0.0.6.9.9.5.5 (user goal)
[__1] unknown package: wikiparsec (dependency of gargantext)
[__1] fail (backjumping, conflict set: gargantext, wikiparsec)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: gargantext, wikiparsec

Cleaning up file based variables
ERROR: Job failed: exit code 1