Code to support react based UI for diagnostics:
* pprof, prometheus and diagnistics rationalized to use a single router
(i.e. they can all run in the same port)
* support_cmd updated to support node routing (was only first node)
* Multi content support in router tunnel (application/octet-stream &
appliaction/json)
* Routing requests changed from using http forms to rest + query params
* REST query requests can now be made against erigon base port and
diagnostics with the same url format/params
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Co-authored-by: dvovk <vovk.dimon@gmail.com>
Co-authored-by: Mark Holt <mark@disributed.vision>
