Scalafix rules for Monocle 3

Monocle 3 deprecates lots of methods, it would be great to use scalafix to automatically refactor the ones that have replacements. Here is a list of changes:

• set to replace
• setOption to replaceOption

Shortcuts for popular optics

• composeLens(at(x)) to at(x)
• composePrism(some) to some
• composeOptional(index(x)) to index(x)
• composeTraversal(each) to each
• composeTraversal(filterIndex(predicate)) to filterIndex(predicate)
• composeLens(first) or composeLens(_1) to at(1)
• composeLens(second) or composeLens(_2) to at(2)
• composeLens(third) or composeLens(_3) to at(3)
• composeLens(fourth) or composeLens(_4) to at(4)
• composeLens(fifth) or composeLens(_5) to at(5)
• composeLens(sixth) or composeLens(_6) to at(6)
• composeOptional(headOption) to index(0)

Overloaded compose method

• composeFold(x) to andThen(x)
• composeGetter(x) to andThen(x)
• composeIso(x) to andThen(x)
• composeLens(x) to andThen(x)
• composePrism(x) to andThen(x)
• composeOptional(x) to andThen(x)
• composeTraversal(x) to andThen(x)
• composeSetter(x) to andThen(x)

Remove symbolic compose operators

• ^|->> x to andThen(x)
• ^|-? x to andThen(x)
• ^<-? x to andThen(x)
• ^|-> x to andThen(x)
• ^<-> x to andThen(x)

ApplyOptics

• applyLens(at(x)) to optics.at(x)
• applyPrism(some) to optics.some
• applyOptional(index(x)) to optics.index(x)
• applyTraversal(each) to optics.each
• applyTraversal(filterIndex(predicate)) to optics.filterIndex(predicate)
• applyLens(first) or applyLens(_1) to optics.at(1)
• applyLens(second) or applyLens(_2) to optics.at(2)
• applyLens(third) or applyLens(_3) to optics.at(3)
• applyLens(fourth) or applyLens(_4) to optics.at(4)
• applyLens(fifth) or applyLens(_5) to optics.at(5)
• applyLens(sixth) or applyLens(_6) to optics.at(6)
• applyOptional(headOption) to optics.index(0)
• applyFold(x) to optics.andThen(x)
• applyGetter(x) to optics.andThen(x)
• applyIso(x) to optics.andThen(x)
• applyLens(x) to optics.andThen(x)
• applyPrism(x) to optics.andThen(x)
• applyOptional(x) to optics.andThen(x)
• applyTraversal(x) to optics.andThen(x)
• applySetter(x) to optics.andThen(x)

Reference: https://github.com/fthomas/scala-steward/blob/master/docs/scalafix-migrations.md

Originally proposed in https://github.com/optics-dev/Monocle/issues/684

Start with the Scalafix migration reference in docs/scalafix-migrations.md and the linked Monocle issue 684. Implement rules covering the checked-list transformations for deprecated methods, shortcuts, compose operators, and ApplyOptics, then verify that each listed migration is handled safely.