fungible conformance tests: Inspect and Mutate (#13852)

* typo

* - create test files for each fungile trait
- begin implementing tests for the Inspect trait

* wrap inspect tests in a macro

* first run of mutate tests

* move test implementation out of ballances

* make tests more generic

* transfer tests

* combine inspect and mutate tests

* set balance failing tests

* can_deposit tests

* can_withdraw tests

* test reducible_balance

* remove balanced stub

* revert set_balance return val fix

* typo

* macro and dust trap tests

* disable test when it doesn't make sense

* remove debug comment

* reduce macro boilerplate

* improved var naming

* improve variable naming

* remove redundant comment

* remove placeholder tests

* remove placeholder tests

* simplify macro

* Update frame/balances/src/tests/fungible_conformance_tests.rs

Co-authored-by: Kian Paimani <[email protected]>

* use Balance from T

* fix copyright

* add test doc comments

* improve test naming

* clippy

* fix rustdoc errors

* fix rustdoc

* improve macro

* improve variable naming

* remove redundant comment

* use path

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Co-authored-by: Kian Paimani <[email protected]>