Add units to JSON RPC Report to clearly state the performance

[nazar-kuzo]

Is your feature request related to a problem? Please describe. Right now JSON RPC Report shows the information about time taken to perform different RPC calls but it is not clear which time units are presented there, mistakenly I assumed that time is shown in milliseconds (ms) but as it was explained by @MarekM25 it is actually in microseconds (μs).

Current JSON RPC Report

Describe the solution you'd like To avoid future confusions I suggest to add units of time measure to a JSON RPC Report header so users will be able to clearly understand the performance rather than predict on their (wrong) assumptions

Describe alternatives you've considered None

Additional context

Suggested JSON RPC Report with units in header