Support BaguaStrategy with external implementation (#17029)

* Support BaguaStrategy with external implementation

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* add an introduction of BaguaStrategy

* update the introduction of BaguaStrategy

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Apply suggestions from code review

* link

* Fix document formatting issues

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* update lightning-bagua version

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* update lightning-bagua version

* Apply suggestions from code review

---------

Co-authored-by: Yafen Fang <fangyaf@spaceml1.ethz.ch>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: Jirka <jirka.borovec@seznam.cz>