feat(lsp): support textDocument/documentColor

test(lsp): add tests form `vim.lsp.document_color`

runtime/lua/vim/lsp/protocol.lua

@@ -532,6 +532,9 @@ function protocol.make_client_capabilities()
       callHierarchy = {
         dynamicRegistration = false,
       },
+      colorProvider = {
+        dynamicRegistration = false,
+      },
     },
     workspace = {
       symbol = {