[eglot] Add support for eglot lsp client in emacs

- Update README
- Add eglot-specifics to cc, rs, py, hs
  removing unused lsp-mode packages when eglot is active
- Add eglot-specific bindings
- Add doctor warnings for debugger +lsp and +peek
- Add eglot-backed lookup-handlers
- Add flycheck checker using eglot for :checkers
  syntax users (using flycheck/flycheck#1676 and
  flycheck/flycheck#1592 discussion).
  This implementation is based on @marsam code, and uses recent
  Flycheck development in order to make the code smaller and
  easier to maintain.

modules/lang/python/config.el

@@ -22,7 +22,10 @@ called.")
         python-indent-guess-indent-offset-verbose nil)
 
   (when (featurep! +lsp)
-    (add-hook 'python-mode-local-vars-hook #'lsp!))
+    (add-hook 'python-mode-local-vars-hook #'lsp!)
+    ;; Use "mspyls" in eglot if in PATH
+    (when (executable-find "Microsoft.Python.LanguageServer")
+      (set-eglot-client! 'python-mode '("Microsoft.Python.LanguageServer"))))
   :config
   (set-repl-handler! 'python-mode #'+python/open-repl :persist t)
   (set-docsets! 'python-mode "Python 3" "NumPy" "SciPy")
@@ -98,6 +101,7 @@ called.")
       "Enable `anaconda-mode' if `lsp-mode' is absent and
 `python-shell-interpreter' is present."
       (unless (or (bound-and-true-p lsp-mode)
+                  (bound-and-true-p eglot--managed-mode)
                   (bound-and-true-p lsp--buffer-deferred)
                   (not (executable-find python-shell-interpreter)))
         (anaconda-mode +1))))
@@ -286,7 +290,7 @@ called.")
 
 
 (use-package! lsp-python-ms
-  :when (featurep! +lsp)
+  :when (and (featurep! +lsp) (not (featurep! :tools lsp +eglot)))
   :after lsp-clients
   :preface
   (after! python