feat(eslint-plugin): [ban-types] tighten defaults

`Record<string, any>` is not typesafe, so we shouldn't suggest it as the default fixer.
Additionally, using `any` causes errors via the `no-explicit-any` rule.

`Record<string, unknown>` is safe because you have to use type guards to actually use the value.
Also add handling for `object`; it wasn't added because I didn't think about the fact that it's not fixing `Object` -> `object` like the rest of the fixers.

Fixes #842

packages/eslint-plugin/src/rules/ban-types.ts

@@ -102,8 +102,12 @@ export default util.createRule<Options, MessageIds>({
           fixWith: 'number',
         },
         Object: {
-          message: 'Use Record<string, any> instead',
-          fixWith: 'Record<string, any>',
+          message: 'Object is not type safe, use Record<string, unknown> instead',
+          fixWith: 'Record<string, unknown>',
+        },
+        object: {
+          message: 'Object is not type safe, use Record<string, unknown> instead',
+          fixWith: 'Record<string, unknown>',
         },
         Symbol: {
           message: 'Use symbol instead',