Calculate BitVM with dummy winternitz at init (#498)

* Calculate BitVM with dummy winternitz at init

* Add bitvm caching

* Use lazy static

* Remove ctor

* Add dummy bitvm creation in debug mde

* Fix merge bug

* fmt

* remove printlns, re-enable deposit test

* fmt

* Fix bug with debug mode, remove lints

* fmt and clippy

* Fix unwraps, return Result when needed

* Fix error in release mode