Add ability to capture variables from all frames

**Describe the idea**
I am currently using the `include_local_variables` flag to capture the top frame's variables on an exception. AFAIK there isn't support for capturing variables for all frames, only the top frame. I am curious if it is possible to report variables for all frames in the stack as an option as well.

**Why do you think it's beneficial to most of the users**

In my case, it would help a ton to debug why an error is occurring to understand how to solve it. For example, there is an exception being raised by an HTTP request, but the part I am trying to understand is *how* that request was constructed, not why the exception was raised when executing that request (the wrong request is being sent).

**Possible implementation**

I am not sure if this is possible in Ruby!

I see the [current implementation](https://github.com/getsentry/sentry-ruby/blob/a7bc13ed200756aea00a3ed8a3e0abe0715e6ab9/sentry-ruby/lib/sentry-ruby.rb#L57-L58) gets the binding using TracePoint, and then gets the variables from that.

I don't know in ruby if you can navigate up the stack in an exception handler like this.