Add suport for type on code selection.

This adds in initial support, but this issue in Metals
should be merged in first: scalameta/metals#3178.

Closes scalameta#228

lua/metals.lua

@@ -356,6 +356,13 @@ M.show_javap_verbose = function()
   ))
 end
 
+M.type_of_range = function()
+  local start = vim.api.nvim_buf_get_mark(0, "<")
+  local vend = vim.api.nvim_buf_get_mark(0, ">")
+  local range = vim.lsp.util.make_given_range_params(start, vend)
+  vim.lsp.buf_request(0, "textDocument/hover", range)
+end
+
 -- Since we want metals to be the entrypoint for everything, just for ensure that it's
 -- easy to set anything for users, we simply include them in here and then expose them.
 M.bare_config = setup.bare_config