Docs/submission diagram update

[blankdots]

Describe the pull request:

• Code cleanup
• Build system change
• Documentation change

Changes made:

• make use of mermaid diagrams to update database schema, submission workflow, GA4GH visas workflow
• introduce mermaid diagram rendering
• remove some outdated css and outdated sequence submission workflow diagram
• update data out to be data retrieval (to have a consistent language)

Related issues:

Additional information:

• Diagrams are not that visible on a small screen, and i tried looking for zooming options, but failed short there

Release note:

Documentation change:

Mentions:

@aaperis apologies about taking the task related to db, but i found this: https://github.com/KarnerTh/mermerd that helped me generate the diagram. Still feel free to make changes

[kjellp]

Nice improvements! The database and submission pipeline mermaid diagrams were quite tiny, and since they are not pictures, they cant easily be mangnified in a separate viewer. Firefox zoom (ctrl-+) only enlarge the text of the page and not really the diagram text (or the effect is not really that noticable).

[aaperis]

Nice! The only problem is as @kjellp mentioned that the diagram details can be very hard to read.

[blankdots]

we could split the diagrams or try to find a way to zoom into them

I know at least on github there is a way to zoom

for now merging,