[WIP] BA to slim BA

[psimovec]

The algorithm for slim automata construction is described in section 3.2 here: https://link.springer.com/content/pdf/10.1007%2F978-3-030-45190-5_17.pdf (seminator --slim --strong --via-tba)

Latest jupyter notebook demo: https://github.com/psimovec/seminator/blob/ba2slim/notebooks/slim_ba.ipynb

Step 1 ✔️
extract BP algorithm from bp_twa
relevant jupyter notebook

Step 2 ✔️ ⚠️
add "slim" transitions
⚠️ done, but breaks bp_twa class
relevant jupyter notebook
fix this in follow-up commits ✔️

Step 3 ✔️
Change --slim from being desired output to classic argument..
add --bp argument to display BP automaton
relevant notebook

Step 4 : ✔️
Fix bug in construction that @xblahoud pointed out here (bug), thanks!
fixed: notebook with fix

Step 5: ✔️
add tests for slim automata

Step 6: ✔️ ❓
"done", the algorithm looks that works, and the tests pass. But it's correctness isn't proved or anything like that.

Step 7: ✔️
BP and slim edges distinguished by belonging to a different accepting state set ✔️
better visualization of slim automata - a different color for bp/slim edges/states ✔️

Step 8: TODO, or not TODO, that is the question
move BP algorithm from slim constructor to bp_twa method to get rid of unnecessary changes of private properties to public

alternative - just rename slim class to some kind of breakpoint automaton, and bp_twa would use this...

TODO:
pure BP algo might not be working
use better names of variables
create tests of language equivalence on random generated automata
on input/slim/ weak slim
random generated could have TGBAs.. On test failure it could give a hint if something is needed to change..
generalize for TGBA

If slim.test fails, we can check output of --grind if it failed on LTLs where the ltl or it's negation generates TGBA with anything else than 1 accepting set
#!/bin/zsh
while read -r line; do echo $line;ltl2tgba $line|grep "Acceptance: [^1]";ltl2tgba --negate $line|grep "Acceptance: [^1]"; echo ""; done < grind.ltl