Remove "stack solver" command

"stack solver" command is no longer available

Cf. https://github.com/commercialhaskell/stack/releases/tag/v2.1.1

Support for GHC 8.10

Merge pull request #1190 from gibiansky/dependabot/npm_and_yarn/jupyterlab-ihaskell/node-fetch-2.6.1

build(deps): bump node-fetch from 2.6.0 to 2.6.1 in /jupyterlab-ihaskell

Bumps [node-fetch](https://github.com/bitinn/node-fetch) from 2.6.0 to 2.6.1.
- [Release notes](https://github.com/bitinn/node-fetch/releases)
- [Changelog](https://github.com/node-fetch/node-fetch/blob/master/docs/CHANGELOG.md)
- [Commits](https://github.com/bitinn/node-fetch/compare/v2.6.0...v2.6.1)
Signed-off-by: dependabot[bot] <support@github.com>

build(deps): bump notebook from 6.0.3 to 6.1.5

Bumps [notebook](https://github.com/jupyter/jupyterhub) from 6.0.3 to 6.1.5.
- [Release notes](https://github.com/jupyter/jupyterhub/releases)
- [Changelog](https://github.com/jupyterhub/jupyterhub/blob/master/CHECKLIST-Release.md)
- [Commits](https://github.com/jupyter/jupyterhub/commits)
Signed-off-by: dependabot[bot] <support@github.com>

add codemirror command line flag

update ihaskell jupyterlab extension and align directory name

Bump mimetypes of vega