soroban-rpc: Use soroban-tools Crates #22

Job	Run time
Build (ubuntu-latest, x86_64-unknown-linux-gnu, amd64)	2m 21s
Integration tests (ubuntu-20.04, 1.21, .CLI.)	21m 0s
Build (ubuntu-latest, aarch64-unknown-linux-gnu, arm64)	2m 53s
Integration tests (ubuntu-20.04, 1.21, ^Test(([^C])\|(C[^L])\|(CL[^I])).*$)	19m 29s
Build (macos-latest, x86_64-apple-darwin, amd64)	3m 18s
Build (macos-latest, aarch64-apple-darwin, arm64)	5m 34s
Integration tests (ubuntu-22.04, 1.21, .CLI.)	20m 15s
Build (windows-latest, x86_64-pc-windows-gnu, amd64)	7m 27s
Unit tests (ubuntu-20.04, 1.21)	5m 58s
Integration tests (ubuntu-22.04, 1.21, ^Test(([^C])\|(C[^L])\|(CL[^I])).*$)	19m 37s
Unit tests (ubuntu-22.04, 1.21)	6m 4s
	1h 53m 56s

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