Make some improvements to java +lsp

This is a first pass at making `+lsp` more functional:

* Fix lsp not starting automatically when opening java-mode buffers.
Placing it in the lsp-java hook does not work.
* Enable the code lens for test classes.
* Add a keybinding/function to easily update the eclipse LSP server.
* Add a keybinding to bring up the lsp-jt-browser (the treemacs based
browser that lists all the project tests).
* Fix root path for lsp-jt.

There are still a lot of rough edges here, and I don't think it's quite
usable yet, mostly due to issues around the java test mode (lsp-jt). The other
functionality all seems to work well though.

modules/lang/java/+lsp.el

@@ -1,13 +1,25 @@
 ;;; lang/java/+lsp.el -*- lexical-binding: t; -*-
 ;;;###if (featurep! +lsp)
 
+;;;###autoload
+(defun +java/update-lsp-server ()
+  (interactive)
+  (lsp--install-server-internal (gethash 'jdtls lsp-clients) t))
+
+(add-hook! java-mode-local-vars #'lsp!)
+(map! :map java-mode-map
+      :localleader
+      :desc "Update the Eclipse LSP server" "U" #'+java/update-lsp-server
+      :desc "Open the test browser" "T" #'lsp-jt-browser)
+
+;; TODO: This fails on the first java buffer opened - complains about the LSP server not having executeCode capabilities.
+(defun java--lsp-jt-lens-mode-hook ()
+  (when (derived-mode-p 'java-mode) (lsp-jt-lens-mode)))
+
 (use-package! lsp-java
-  :after lsp-clients
-  :hook (java-mode-local-vars . lsp!)
+  :after (lsp-clients dap-mode)
+  :hook (lsp-mode . java--lsp-jt-lens-mode-hook)
   :preface
   (setq lsp-java-server-install-dir (concat doom-etc-dir "eclipse.jdt.ls/server/")
-        lsp-java-workspace-dir (concat doom-etc-dir "java-workspace"))
-  :config
-  ;; TODO keybinds
-  ;; TODO treemacs integration (?)
-  )
+        lsp-java-workspace-dir (concat doom-etc-dir "java-workspace")
+        lsp-jt-root (concat doom-etc-dir "eclipse.jdt.ls/server/java-test/server")))