Upgrade Invenio packages and support SQLAlchemy 2.0

[GraemeWatt]

New major releases of the Invenio packages have just been made that require SQLAlchemy>=2.0.0. Naively bumping the Invenio packages in the requirements.txt file (see commit on the major-invenio-upgrade branch) gives many failed tests and broken functionality. The SQLAlchemy 2.0 - Major Migration Guide should be followed to migrate the API calls from 1.x to 2.x in the core HEPData code (outside the Invenio modules). Note that an intermediate step is to switch on the SQLALCHEMY_WARN_20 environment variable with SQLAlchemy 1.4 (i.e. installed by the current main branch) and address any warnings that are emitted before switching to SQLAlchemy 2.0.

@ItIsJordan : maybe this is something you can help to address?

[GraemeWatt]

Warning: installing the new Invenio packages via the major-invenio-upgrade branch seems to have wiped my local hepdata database, so a backup should be made before investigating this issue if the local database needs to be preserved.