EDB Connect: Add db query tool

[BedrockSquirrel]

Why this change is needed

EDB is a black box, for testnet debugging we want to be able to peek at data, do maintenance tasks, identify expensive queries etc.

EDB Connect is a REPL-like command line tool that lets you execute arbitrary queries against the secure EDB on a node.

This PR adds a script ./edb-connect.sh to the obscurouser home dir, which when executed pulls the latest edb-connect image and starts the CLI tool. It tries to clean up after itself and should support simultaneous running on the same box.

This PR also adds a github action that can be run from main or any branch to publish a new 'latest' edb-connect image. This allows us to tweak the tool when debugging without having to do a network upgrade or manual fiddling to get the changes.

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[tudor-malene]

LGTM.

(minor comment)

[tudor-malene]

this could be 1024.

[StefanIliev545]

Good job!

[StefanIliev545]

Remind me, does the enclave allocate the memory preemptively? If so this might be a bit huge

[BedrockSquirrel]

Yeah good shout I think it might allocate greedily. I'll cut it in half and check it still works

[StefanIliev545]

Have we tested how special characters behave here, considering its coming from stdio? I imagine since its in app the terminal won't be doing any ad hoc bs, but ...

[BedrockSquirrel]

If you press like keys like up and ctrl on the keyboard it does create some garbage characters I think, let me have a look see if I can improve that. Didn't see any weird rendering with the query responses though (although it's not very pretty, nicer formatting and option to dump response to CSV would be useful upgrades).