MBS-13668: Support table homonyms in schema diagrams

[yvanzo]

MBS-13668

Problem

So far the script "write_graphs.pl" was assuming that table names were unique even across schemas. This was correct until the EAA had to be taken into account. There are now two tables "art_type", one in the schema "cover_art_archive" and the other in the schema "event_art_archive".

Solution

• Prefix table names (or "tables" object) with their schema in the JSON source format
• Make the script distinguish between node name and table name

Testing

Regenerated DOT files with the command make graphs/soup.dot

Committed those new DOT files as it will help to compare and see real changes in the future.

Further action

Only node identifiers changed, nothing visibly changed otherwise, so there is no need to upload the SVG files again (which sometimes need manual editing for clean curved lines).