Fix/rpc header

[elizabethengelman]

What

This PR makes sure to use the Network.rpc_client function when getting an rpc client, instead of creating one with Client::new. It's important to do use rpc_client` because it makes sure to pass in additional headers to the rpc client, including adding auth headers which are needed for some rpc providers.

This change was made in:

• Network.helper_url
• get_remote_contract_spec: This was the main reason for the bug reported in Unable to connect to RPC Endpoint that requires API key #1728, because invoke calls get_remote_contract_spec.
• several integration tests

Fixes #1728.

Why

As part of supporting third-party rpc providers, we need to pass in the authentication as a header for some providers. This was done in #1618 , but must have missed making the update to other scenarios that were creating a new rpc client with Client::new.

Known limitations

Curious to hear what others think, but as the rpc client is currently written, it is still possible to create an rpc client with required headers using Client::new. While having the flexibility is nice, does it make sense to deprecate this function and rely on new_with_headers instead? This would be a change made to the rpc client repo.

[willemneal]

Looks good to me!

[leighmcculloch]

While having the flexibility is nice, does it make sense to deprecate this function and rely on new_with_headers instead? This would be a change made to the rpc client repo.

👍🏻. It's breaking so we'd need to delay the actual removal until the next major release, but you could add a deprecated attribute now.

[leighmcculloch]

@elizabethengelman Can you fix the cargo-deny bans issues, try to align on not duplicate deps or if it's not possible, then add a line in the deny toml to allow the dupe deps?

[leighmcculloch]

This PR is blocked on a legal sign off because the http-mock uses a license we don't currently have approved. I expect it'll just be a formality in this case.

[leighmcculloch]

This PR is blocked on a legal sign off because the http-mock uses a license we don't currently have approved. I expect it'll just be a formality in this case.

Unblocked and I pushed a modification to deny.toml for the license approval.

[leighmcculloch]

I think this is good to go, except for the bans need updating.

[leighmcculloch]

I think this is good to go, except for the bans need updating.

[elizabethengelman]

@leighmcculloch cargo-deny bans have been fixed - was able to move httpmock to dev-dependencies to fix this, which it probably should have been anyways.