Performance analysis over time (haskell/ghcide#629)

* benchmark history script

* if HEAD no need to rebuild worktree

* add bench/README.md

* Enable all experiments

* Fix dependency tracking for git branches

* hlints

* Add stack84 extra-deps

* Identify failed experiments in graphs

* Filter our failed benchmarks from aggregate graphs

Otherwise they tend to distort the axis

* Improve graphs (more and easier to see colors)

* update cradles

* customizable output folder

* Cache the config for the duration of the script

Otherwise the script is vulnerable to config edits

* Allow omitting the git: field

* Ignore bench-hist intermediate artifacts

Handy for including bench-hist results in a branch while avoiding the
intermediate artifacts

ghcide/.gitignore

@@ -7,4 +7,9 @@ cabal.project.local
 /.tasty-rerun-log
 .vscode
 /.hlint-*
-bench/example
+bench/example/
+bench-hist/
+bench-temp/
+.shake/
+ghcide
+*.benchmark-gcStats