Manage exchange names between activities

[marc-vdm]

Additional TODO:

• [ ] Write all fields:
  • 'name': 'market for water, completely softened',
  • 'product': 'water, completely softened',
  • 'unit': 'kilogram',
  • 'location': 'RoW',
  • 'categories': None,
  • 'type': 'technosphere',
  • 'amount': 0.0,
  • 'input': ('ei39-remind-SSP2', '4c816450-1179-48fa-a590-ad295d60451c'),
  • 'output': ('ei39-remind-SSP2', '48591ed0-5887-4bcc-b1d4-af14dde5aa47')
• [ ] Make sure all database imports in AB write exchanges properly

As discussed in #1242, AB give names to exchanges when they are created. Storing names in exchanges would be beneficial for:

• Interoperability with lca_algebraic
• Multifunctionality when implemented in the future, as exchanges will have the name of their product, which will help identify which MF product is used in an exchange

Storing these names costs us virtually nothing in code complexity or time when in use.

This PR does:

• Writes source product name on exchange creation
• Updates exchange name when source product name is edited
• In the Exchanges tables in activity details, reads the product from the exchange instead of from the source activity, with appropriate fallbacks in case it doesn't exist yet
• Resolve #1242

Additional notes:

• I tested this with an activity that has downstream consumers (so is the source of an exchange)
  • I then edited the source product name, and the name is added to the exchange, even though it did not exist. This will not be a source of potential errors. I added this info into the docstring.

Checklist

• [x] Keep pull requests small so they can be easily reviewed.
• [x] Update the documentation, please follow the numpy style guide.
• [ ] Update tests.
• [x] Categorize the PR by setting a good title and adding one of the labels: bug, feature, ui, change, documentation, breaking, ci as they show up in the changelog.
• [x] Link this PR to related issues by using closing keywords.
• [x] Add a milestone to the PR for the intended release.
• [x] Request a review from another developer.

[coveralls]

coverage: 50.568% (-0.08%) from 50.652% when pulling eed37b01ff5f48ff12252cf690a21685834edfd4 on marc-vdm:store_exchange_name into ffa5ad8495fcf3743a0ffe5b56cc225dd0d6b7d6 on LCA-ActivityBrowser:master.