[TM-262] Improve optimiser

Description

Description

Following problems exist:

1. linearizeRight has poor performance;
2. Seq a b is not recognised by (Seq a (Seq b c)) rule where c is free;
3. Some non-leaf instructions (MAP) are left unoptimised;
4. optimizeWithRule is not entirely correct;
5. We need type-directed optimisations, like forall (op :: s -> a s). op DROP ==> NOP. These shouldn't erase any possible side-effects.
6. We need more rules (MAP/MAP fusion, MAP/ITER fusion, IF [x] [x] -> DROP x, etc).

I will try to fix these problems.

Related issue(s)

https://issues.serokell.io/issue/TM-262

Changes

I converted recursive application to bottom-up, which frees us from descent into the AST, since all sub-branches are already optimised.

The lineariseRight now goes as far as last Seq (Seq _ _) _ node and reapplies ruleset on each node re-appended from LHS to RHS.

✅ Checklist for your Merge Request

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