Expand docs around SV network diagram

[canton-network-da]

[ This issue was auto-migrated from DA's internal repo (DACH-NY/canton-network-node#17979). Original author: @isegall-da ]

From Stas:
Checking the docs: the network diagram is a big help, but the documentation does not explain which ports are supposed to be whitelisted (source, destination, reason and notes, e.g. VPN to SV for automatic validator onboarding (DevNet only), etc)

[canton-network-da]

[ from @moritzkiefer-da ]: I'm somewhat struggling to understand what exactly he is after. Here is the diagram https://dev.network.canton.global/_images/sv-network-diagram.png

The ports exernally are all 443 which is already implied by the HTTPS link with the exception of cometbft. I guess we can include the port there if we want.
And all components list exactly who they shoudl be exposed to?

[canton-network-da]

[ from @isegall-da ]: Good question. I blindly copied his comment from the agenda during the meeting without questioning it. I'll followup with Stas to get clarifications.

[canton-network-da]

[canton-network-da]

[ from @moritzkiefer-da ]: Slack discussion

Based on that, this seems less about ports but I agree with Stas that we're missing some stuff. I'd solve it by adding some text description of the diagram, that clearly points out:

1. How you're supposed to use that, i.e, just very explicitly state "should baccessible to validators" means "whitelist that tothe validators in allowed-ip-ranges"
2. Points out the VPN particularities. On devnet, we want "acessible to validators = accessible to vpns", on test and mainnet we want at a minimum "accessible to read-only clients = accessible to vpns".
3. add some more details around the SV onboarding endpoints.

[canton-network-da]

[ from @moritzkiefer-da ]: @martinflorian-da while you're at it, let's mention that /api/sv/version must also be whitelisted for validators to be able to connect not just the two (including devnet self-serve secret) onboarding endpoints.

[canton-network-da]

while you're at it

I must admit forgot about this last week and will only get to it towards end of this week the earliest. Please whoever cares deeply about these improvements - snatch it from me.