[cmake] Add a target for the proof-manager-cli tool

Summary:
Make it easy to build (via ninja) and install (via install-proof-manager-cli) the proof manager CLI tool.

Note that this is still gated behind a flag to avoid making Rust a mandatory dependency for the node.

Depends on D18956.

Test Plan:

cmake -GNinja .. -DBUILD_PROOF_MANAGER_CLI=ON
ninja # Builds the proof-manager-cli
ninja install-proof-manager-cli
ninja check-proof-manager-cli

./contrib/teamcity/build-configurations.py proof-manager-cli

Reviewers: #bitcoin_abc, PiRK

Reviewed By: #bitcoin_abc, PiRK

Subscribers: PiRK

Differential Revision: https://reviews.bitcoinabc.org/D18958