Rework exceptions and stacktraces

[kuhnroyal]

An evaluation of how DioException can work with better stack traces that can be catched while still being aware of the cause and the stack trace of the cause.
Related to #1914

• rename DioException.error to DioException.cause
• add DioException.causeStackTrace
• get rid of RequestOptions.sourceStackTrace property
• use Error.throwWithStackTrace to throw all errors with the manually captured stack trace at a single point in DioMixin
• extract some inner functions inside DioMixin.fetch to prevent them capturing the state of requestOptions and cancelToken variables, instead pass them as arguments

New Pull Request Checklist

• I have read the Documentation
• I have searched for a similar pull request in the project and found none
• I have updated this branch with the latest main branch to avoid conflicts (via merge from master or rebase)
• I have added the required tests to prove the fix/feature I'm adding
• I have updated the documentation (if necessary)
• I have run the tests without failures
• I have updated the CHANGELOG.md in the corresponding package

Additional context and info (if any)