Breaking Changes in v4.0.0

This issue lists features removed and other breaking changes in ALE v4.0.0.

## Removed Features

1. `:ALEInfoToClipboard` - Use `:ALEInfo -clipboard` or the plug mapping instead.
2. The quite old fallback setting name `g:ale_linters_sh_shell_default_shell` has been removed. Use `g:ale_sh_shell_default_shell` instead.
3. The quite old fallback setting name `g:ale_linters_sh_shellcheck_exclusions` has been removed. Use `g:ale_sh_shellcheck_exclusions` instead.
4. The old `ale_lsp_root` setting is no longer supported. Use `ale_root` instead.

## Older Tools Support Removed

1. `ember-template-lint` versions below 1.6.0 are no longer supported.

## Other Breaking Changes

1. #4481 The `ve-py3` directory name is no longer among the names ALE searches for by default for virtualenv directories. Set your `g:ale_virtualenv_dir_names` setting if you still need it.

## New Deprecations

1. Use the `ale_deno_import_map` option for the Deno import map instead of `ale_deno_importMap`.