Added eels parser. Improved experiment url handling.

.gitmodules

dependencies/nomad-meta-info

dependencies/parsers/eels

dependencies/python_common

gui/src/components/ems/EMSEntryCards.js

gui/src/components/ems/EMSEntryOverview.js

nomad/cli/parse.py

nomad/datamodel/ems.py

nomad/parsing/__init__.py

nomad/parsing/backend.py

nomad/parsing/parser.py

tests/data/parsers/aptfim.aptfim

tests/data/parsers/eels.json

tests/data/parsers/mpes.meta

tests/test_normalizing.py

tests/test_parsing.py