feat(lsp): support completion context #32793

Problem:
vim.lsp.completion with "autotrigger" enabled, does not send
completion context, even though it has all the necessary info.

Solution:
Include the context for "autotrigger".
trigger() also optionally accepts context when manually invoked.

runtime/lua/vim/lsp/protocol.lua

@@ -476,9 +476,7 @@ function protocol.make_client_capabilities()
             'data',
           },
         },
-
-        -- TODO(tjdevries): Implement this
-        contextSupport = false,
+        contextSupport = true,
       },
       declaration = {
         linkSupport = true,