feature: add document nodes create at and modified at attributes

[ClemDoum]

TODO:

• merge fix: negatively acknowledge error only after it has been saved #136

PR description

Adding document nodes createdAt and modifiedAt attributes (attribute names chosen to match the follow the money schema). These attributes are read from ES document metadata.

While reading the ES metadata, we look for the DC terms created/modified metadata in priority since it's the one used in the datashare-api to define the Docuemnt.getCreationDate() (tika_metadata_dcterms_modified). In case these metadata are not found we fallback to other tika metadata.

The fallback order to creation date is :

• tika_metadata_dcterms_created_iso8601
• tika_metadata_creation_date_iso8601
• tika_metadata_date_iso8601

for modification date it is:

• tika_metadata_dcterms_modified_iso8601
• tika_metadata_last_modified_iso8601
• tika_metadata_modified_iso8601
• tika_metadata_last_save_date_iso8601
• tika_metadata_pdf_docinfo_modified_iso8601
• tika_metadata_date_iso8601

Changes

neo4j-app

Added

• updated the regular and admin imports to add createdAt and modifiedAt attributes to the Document nodes
• added a indexes to Document nodes to be looked up and sorted by createdAt and modifiedAt dates

[caro3801]

Looks good to me. The code is well tested and the migration system is smooth, I like the fallback date attribute attention. Nice addition ! However, I'm not sure to catch why the CI is red

[ClemDoum]

Thanks for the review @caro3801

[ClemDoum]

Thanks for spotting the CI, actually, there was this bug #136 which made tests flaky