[v2] ClientSession runs on JSONRPCDispatcher; BaseSession removed #2639

Job	Run time
checks / readme-snippets	11s
checks / pre-commit	37s
checks / test (3.12, locked, ubuntu-latest)	57s
checks / test (3.10, locked, windows-latest)	1m 23s
checks / test (3.11, locked, ubuntu-latest)	52s
checks / test (3.11, lowest-direct, ubuntu-latest)	55s
checks / test (3.13, locked, ubuntu-latest)	49s
checks / test (3.14, locked, ubuntu-latest)	1m 54s
checks / test (3.12, lowest-direct, ubuntu-latest)	56s
checks / test (3.13, lowest-direct, ubuntu-latest)	52s
checks / test (3.10, lowest-direct, windows-latest)	1m 14s
checks / test (3.10, locked, ubuntu-latest)	54s
checks / test (3.14, locked, windows-latest)	2m 7s
checks / test (3.12, lowest-direct, windows-latest)	1m 30s
checks / test (3.12, locked, windows-latest)	1m 14s
checks / test (3.14, lowest-direct, windows-latest)	1m 18s
checks / test (3.11, lowest-direct, windows-latest)	1m 20s
checks / test (3.13, locked, windows-latest)	1m 13s
checks / test (3.10, lowest-direct, ubuntu-latest)	54s
checks / test (3.13, lowest-direct, windows-latest)	1m 25s
checks / test (3.11, locked, windows-latest)	1m 27s
checks / test (3.14, lowest-direct, ubuntu-latest)	49s
all-green	4s
	24m 55s

Provide feedback