try-runtime: add cli option --export-proof (#12539)

* try-runtime: add cli option --export-proof

* extract proof in raw json format

* fix build

* fix(try-runtime execute-block): wrong block parsing

* fmt

* apply suggestions

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Anton <anton.kalyaev@gmail.com>

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Anton <anton.kalyaev@gmail.com>

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Anton <anton.kalyaev@gmail.com>

* Update utils/frame/try-runtime/cli/src/lib.rs

Co-authored-by: Anton <anton.kalyaev@gmail.com>

* split off external dependencies

* fmt

* fix try-runtime compilation

Co-authored-by: Anton <anton.kalyaev@gmail.com>