[Utility] Warning for missing ruleset name

[oflatt]

In egglog programs, we often add things to rulesets and run these rulesets. Forgetting to add a ruleset has been a big source of bugs in egglog programs.

We should add a feature that allows an error when a ruleset is not provided. We have several options here.

1. We could add a "strict" mode using set-option that throws an error when a ruleset is not provided
2. We could detect if a ruleset was never run and print a warning in that case

Or we could do both of those

[yihozhang]

It is tedious to give specify the ruleset for each rule, and for simple programs people just want their rule to be in the default rule set. I think a better design is just to have a different syntax for rulesets so that it is impossible to forget. What do you think?

(ruleset optimization

  (rule (...) (...))
  (rule (...) (...))
  ...
)

[oflatt]

Yeah, that would be good too!

[oflatt]

I'm just putting this on the board as an issue to address more urgently