initial commit: Jupyter notebook to help estimate network settings

[MonsieurNicolas]

This PR adds a notebook with rudimentary support for estimating disk iops/bandwidth and network utilization.

This is just a starting point, and is probably quite off (impact of bucketlist merges, eviction and archival is not included), but should still allow to reason at the right order of magnitude when making changes.

Over time, this can be extended as to better help estimate limits (both tx level and ledger level) used in Soroban and elsewhere, especially limits that should "never be reduced" in the future.

This version outputs the following:

ledger_LE_reads:  50000
ledger_bytes_read:  28775000
ledger_LE_writes:  25000
ledger_bytes_write:  3175000
ledger_classic_LE_reads:  500000
ledger_classic_bytes_read:  291000000
ledger_classic_LE_writes:  250000
ledger_classic_bytes_write:  35000000
ledger_soroban_LE_reads:  800000
ledger_soroban_bytes_read:  1474560000.0
ledger_soroban_LE_writes:  250000
ledger_soroban_bytes_write:  665600000.0

...

flooding bytes (per connection):  147500000.0
TxSet bytes:  59000000
Network bps (GBit/s):  3.1663477420806885

...

max iops:  1963575.4285714286
max read Mbps:  2463.800726209368
max write Mbps:  2684.6885681152344
max disk bandwidth Mbps:  2703.9018592834473

which is in line with our expectation that NVMe drives will probably be needed as tps increases

[anupsdf]

LGTM! Tested this running in Jupyter lab online tool.