* Fix mutable default

* LayerChoice:forward now will default run the first candidate to support trace (#3910)

* New GraphConverter to parse shape info required by nn-meter (#3910)

* Support model filter in Random strategy

* Support latency aware search in SPOS multi-trial example

* Fix for review (#3910)

* Add doc for hardware-aware NAS

* Fix lint python & Add nn_meter to sphinx mock

* Add comments

* Move LatencyFilter to examples

* Move example inputs into configs

* Support nested layer choice

Co-authored-by: Jianyu Wei <v-wjiany@microsoft.com>
Co-authored-by: kalineid <nnob@mail.ustc.edu.cn>
Co-authored-by: Yuge Zhang <scottyugochang@gmail.com>
Co-authored-by: Yuge Zhang <Yuge.Zhang@microsoft.com>