tasks #7286: Add empty file indexation

This task is part of the story #7230 be able to search for folder, links
and empty files (metadata) in docman

Change-Id: I7fb008cde12ff1b945bca9511b882329b58b670b
tasks #7287: Add link indexation

This taks is part of story #7230 be able to search for folder, links and
empty files (metadata) in docman

Change-Id: Ib61e28898967b2f709f8206080c5551a19142b9b
tasks #7289: Reindex content when metadata are updated

This is task is part of story #7230 be able to search for folder, links
and empty files (metadata) in docman

Change-Id: Ic41c090a8f36d19371fa0e9948c387f6fd6ee516
tasks #7284 Add folder indexation

This task is part of story #7230 be able to search for folder, links and
empty files (metadata) in docman

Change-Id: I30987f152ccd4b537c6efb1716520a17bd294b6a
Merge commit 'refs/changes/26/2826/1' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #7284 Add folder indexation
  tasks #7289: Reindex content when metadata are updated
  tasks #7287: Add link indexation
  tasks #7286: Add empty file indexation

Change-Id: I75585dafd2fd670d5990f849519897378889836a
Tuleap 7.3.99.15

Change-Id: I5e8b3a84bca6447d3f869fd6bc46082902720d5a