Display idb::Error in Error

[John-Toohey]

Under the current implementation, when a rexie::Error::IdbError is raised, very little information is given.

Consider the following (taken from inside my project with at least several layers of error types):

Whilst everything seems very erroneous, what the error is remains largely a mystery.

Now, with this patch, consider this:

I now have somewhere to base my debugging on.

[devashishdxt]

Instead of adding all the details in Display implementation, you can use Debug to get all the details in your alert (use {:?} instead of {}).