Directory structure refactoring

[gavento]

Done with the bulk of refactoring in dc8b703. Here are some notes on WIP (hastily scribbled, though).

Outstanding structural items:

• [x] Rename text module
  • Some variants: formats
  • Alternatives: move under utils, making utils a first-class package
  • then it would make sense to create a json, text and format_str submodules etc
  • [x] Maybe: move Blob&HTML there as well from contexts if it is changed to formats or content (nah)
  • leave data.py under context, though
• [x] Rethink the name of models
  • variants: query, queries, query_llm, llms, llm, model, lang_models, ... Possibly separate outengines`
• [x] Maybe: rename interactions (too long? also no games yet, but would make more sense with games/scenarios)
  • Option: just bring actor and memory to top-level (Event can stay under actor)
  • maybe it is fine as is, though
• [x] Name of interlab_zoo
  • Options: bazaar, theater, zoo, garden, contrib, ...
  • Have a separate tests dir for zoo?
• [x] Use QueryFailure in our code
• [x] Have repeat_on_failure? (in experimental now)

Outstanding smaller items:

• [x] utils - cleanup, structure a bit
• [x] Be consistent with *Base class naming, add abstract methods (abc)
• [x] Rename __log__ (to _to_context_data?)
• [x] Rename ConsoleAgent to WebConsoleAgent (already done for *Engine)
• [x] Update notebooks
• [x] Update readme (also add the logo)
• [x] Every module to have its own logging
• [x] Use FormatStr in actors and memory (?)

Remaining items (postponed after UI merge, minor issues)

• better colors for actor and UI; test it
  • Use LCh instead of HLS for random color?

[gavento]

All tasks from above are done, ready to merging and bump to 0.3.0 when UI is rebased into this. @spirali, would you please rebase the UI code, and include a built version? (if you are ready)