* add selection range support

* add the whole import area as a selection step

* add selection range plugin to all project files

* merge type signature with value definition

* support ghc 9

* fix it for ghc-9.0

* remove unnecessary import

* reformat GhcIde.hs

* selection range: make it easier to understand

* selection range: improve error handling

* update lsp-types to 1.4.0.1

* add selection range to doc

* fix comment for findSelectionRangesByPositions

* remove a use of partial function

* update author & maintainer

* use foldlM1 instead of foldl1

* add testdata to cabal file

* update performace tips and log level

* update lsp-types in nix

Co-authored-by: Pepe Iborra <pepeiborra@gmail.com>