* some improvements to bounded vec

* revert license tweak

* more tests

* fix

* Update frame/support/src/storage/bounded_vec.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* add the same stuff for btree map and set as well

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>