* add fixed u128

* update fixed-u128

* fix: divide 0 will panic

* fix: will use u128::max_value() when try_into failued in div and mul functions

* test: add checked_div test

* rename: palette to frame

* update fixed-128

* remove add/sub/mul/div operator

* add overflow/underflow tests

* add linked item

* fix ignore

* add tests for linked_item