* remove unneeded loop in `SpliceMutator::mutate`
previously we searched for the first and the last difference
between exactly the same 2 inputs 3 times in a loop
* remove unused struct fields
* avoid allocating strings for `Transition`s
* avoid allocating `String`s for `Stack`s
* avoid allocating Strings for `Element`s
* apply some clippy lints
* some more clippy lints
* simplify regex
* remove superflous if condition
* remove the Rc<_> in `Element`
* small cleanups and regex fix
* avoid allocating a vector for the culled pda
* bug fix
* bug fix
* reintroduce the Rc, but make it use the *one* alloced VecDeque this time
* slim down dependencies
* use Box<[&str]> for storted state stacks
this saves us a whopping 8 bytes ;), since we don't have to store
the capacity
* revert the changes from 9ffa715c10089f157e4e20563143a2df890c8ffe
fixes a bug
* apply clippy lint
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Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>
c791a23456