`safe` API - rename `isDefined` to `isDefinedError` for readability

[tresorama]

Describe the feature

No big deal, but I would prefer it.

Current

const orpcClient = ...
const orpcClientSafe = ... 

const result = await orpcClientSafe.demoPost.getAllPosts();
// or 
const result = await safe(orpcClient.demoPost.getAllPosts());

if (!result.isSuccess) {
 if (result.isDefined && result.error.code === 'POST_NOT_FOUND') {
   // handle this case
 }
 // rethrow the error if unknown
 throw result.error;
}

const post = result.data.data.post;

Request

const orpcClient = ...
const orpcClientSafe = ... 

const result = await orpcClientSafe.demoPost.getAllPosts();
// or 
const result = await safe(orpcClient.demoPost.getAllPosts());

if (!result.isSuccess) {
 //             👇
 if (result.isDefinedError && result.error.code === 'POST_NOT_FOUND') {
   // handle this case
 }
 // rethrow the error if unknown
 throw result.error;
}

const post = result.data.data.post;

Additional information

• Would you be willing to help implement this feature?