* is_contract() and caller_is_origin() added to Ext API

* is_contract() exposed in wasm runtime.rs

* + test for is_contract()

* + seal_is_contract benchmark

* caller_is_origin() exposed to wasm/runtime.rs and covered by a test

* + seal_caller_is_origin benchmark

* Update frame/contracts/src/exec.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/exec.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/exec.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/wasm/runtime.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/wasm/runtime.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/wasm/runtime.rs

Co-authored-by: Alexander Theißen <[email protected]>

* Update frame/contracts/src/exec.rs

Co-authored-by: Alexander Theißen <[email protected]>

* identation fix for benchmark macroses; test cosmetic improvement

* benchmark fix

* + is_contract() wasm test

* + caller_is_origin() wasm test

* Apply suggestions from code review

Co-authored-by: Alexander Theißen <[email protected]>

* is_contract() to borrow param instead of taking ownership

* phrasing improved

Co-authored-by: Hernando Castano <[email protected]>

* fixed wasm tests according to @athei

 feedback

* dead code warnings suppressed by unstable-interface attributes

* cargo run --quiet --profile=production  --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_contracts --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/contracts/src/weights.rs --template=./.maintain/frame-weight-template.hbs

Co-authored-by: Alexander Theißen <[email protected]>
Co-authored-by: Hernando Castano <[email protected]>
Co-authored-by: Parity Bot <[email protected]>