lib/options: mkEnum quote default if string

As there's only a handful of call-sites to fix, ensure all `mkEnum`
defaults are passed in as the correct type (tree wide) and change
`mkEnum` to now correctly render string-type defaults "quoted" (like
`mkString` does).

lib/options.nix

@@ -120,7 +120,12 @@ rec {
     mkAttributeSet = default: mkNullable nixvimTypes.attrs ''${default}'';
     mkListOf = ty: default: mkNullable (with nixvimTypes; listOf (maybeRaw ty)) default;
     mkAttrsOf = ty: default: mkNullable (with nixvimTypes; attrsOf (maybeRaw ty)) default;
-    mkEnum = enumValues: default: mkNullableWithRaw (types.enum enumValues) ''"${default}"'';
+    mkEnum =
+      enumValues: default:
+      mkNullableWithRaw (types.enum enumValues) (
+        # TODO we should remove this once `mkDefaultDesc` no longer has a special case
+        if isString default then generators.toPretty { } default else default
+      );
     mkEnumFirstDefault = enumValues: mkEnum enumValues (head enumValues);
     mkBorder =
       default: name: desc:

plugins/lsp/language-servers/ccls.nix

@@ -51,7 +51,7 @@ in
             1
             2
           ]
-          "1"
+          1
           ''
             Change to 0 if you want to save memory, but having multiple ccls processes operating in the
             same directory may corrupt ccls's in-memory representation of the index.
@@ -206,7 +206,7 @@ in
             1
             2
           ]
-          "2"
+          2
           ''
             `ccls` can index the contents of comments associated with functions/types/variables (macros
             are not handled).
@@ -218,12 +218,11 @@ in
           '';
 
       multiVersion =
-        helpers.defaultNullOpts.mkEnum
+        helpers.defaultNullOpts.mkEnumFirstDefault
           [
             0
             1
           ]
-          "0"
           ''
             Index a file only once (`0`), or in each translation unit that includes it (`1`).
 
@@ -282,7 +281,7 @@ in
             1
             2
           ]
-          "2"
+          2
           ''
             Determine whether a file should be re-indexed when any of its dependencies changes
             timestamp.

plugins/utils/molten.nix

@@ -129,12 +129,11 @@ mkVimPlugin config {
     '';
 
     output_win_style =
-      helpers.defaultNullOpts.mkEnum
+      helpers.defaultNullOpts.mkEnumFirstDefault
         [
           false
           "minimal"
         ]
-        "false"
         ''
           Value passed to the style option in `:h nvim_open_win()`.
         '';