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.