Replace paginated endpoints with streams

[lrettig]

paginated endpoints should have some limit. in that case above there will be problems with memory if end is significantly larger than start

i don't know what should be done with paginated endpoints in general, i would probably split them up and replace with object streams:

• activations
• ballots
• txs results
• blocks
• accounts

and more epmeheral streams:

• layer status, only small header (start, hare, tortoise)
• mempool transactions (to track where tx was included)
• proposals

Originally posted by @dshulyak in #165 (comment)