installation: demosite fixtures addition

* Introduces new command `inveniomanage database demosite` to populate
  demosite from fixtures.

* NOTE `inveiniocfg --create-demo-site` is still using sql data for
  testing purposes.

* DEPRECATED `democfgdata.sql` in flavor of `*_fixtures_demosite.py`

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
global: fix remote debugger to work with Flask

* Fixes remote debugger to work with Flask.

* Changes method of enabling remote debugger to use
  CFG_DEVEL_TOOLS

* Removes legacy code profiler.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
signalutils: initial release

* Adds tools for implementing observer-pattern (i.e. decoupling publishers
  of notification from their subscribers).

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
BibFormat: add filtering of indicators in MARCXML

* Adds filtering of indicators in MARCXML via CFG_BIBFORMAT_HIDDEN_TAGS.
  Previously only 3-digit tags could be filtered. (closes #1497)

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
WebStyle: harmonize blueprint method signature

* Ensures InvenioBlueprint method signature is compatible
  with Flask's method signature.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
global: document CFG_DEVEL_TOOLS for Apache

* Adds note on needed Apache configuration for using the integrated
  debuggers.

* Fixes Apache configuration for wsgi processes if any of debugger is
  enabled.

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Co-authored-by: Jiri Kuncar <jiri.kuncar@cern.ch>
bibuploadutils: initial release

* Adds a new function bibupload_record that will write a MARCXML file
  to tmp-shared and call bibupload on it. If collections are provided
  the updates are chunked into several bibupload tasks of 500 records
  each.

Co-authored-by: Samuele Kaplun <samuele.kaplun@cern.ch>
Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>
installation: replace libxslt with lxml

Signed-off-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>