optimize handling multiple rpcs

[onur-ozkan]

To increase performance and reduce resource consumption on runtime, instead of iterating rpc urls for each request, save one(that works) of the http client to the related token/coin's context and use it without doing extra iterations on sending http requests. Only if current http client becomes broken/unavailable somehow, then start the iteration over rpc urls and find one(that works) and replace it with broken/unavailable one.

• example of current multi-rpc handling implementation
• another example

[onur-ozkan]

Do we have any missing implementation of multiple rpcs? @laruh

If not, we can consider this as completed and close the issue

[laruh]

Do we have any missing implementation of multiple rpcs? @laruh

If not, we can consider this as completed and close the issue

Checked repository, I think that's all, we can close it.