[Metrics] Add Client and Version data to access node requests

[bthaile]

Issue to be solved

Need to track versions of fcl being used and failure rates

Suggest A Solution

Add custom header on requests to access node. header name FLOW-CLIENTand FLOW-CLIENT-VERSION

• library name
• library version

example for fcl FLOW-CLIENT=FCL-JS FLOW-CLIENT-VERSION=1.01

What are you currently working on that this is blocking?

Identifying community adoption of new versions as they are released.

[bluesign]

Can we also allow user to add a custom header while doing this? It would be useful for AN providers to (now there is premissionless AN is out) to give out API keys for users

[justinbarry]

@bluesign ~~The ability to add custom headers to the transport is already supported. This would take advantage of that.~~

Work was done here, but the work was incomplete.