feat(pubsub): support message filtering in pstest

[zezhehh]

Resolves #8582

The implementation:

• Parse the filter string using go.einride.tech/aip.
• Match each message attributes with the filter and remove the message if the match fails.

[andreas-lindfalk]

@shollyman review por favor...

[vlasn]

@shollyman Friendly nudge, would love to leverage this.

[hongalex]

Thank you so much for the PR. Apologies as I somehow didn't see this for the longest time. For the most part the PR looks good but I need to confirm with the team on how to tackle this since we generally try to minimize the number of third party libraries.

[zezhehh]

@hongalex Hi! Thanks for your reviews. Just added test for escapes characters and rebased to main.

[hongalex]

Checks are failing because of a minor formatting issue that running go vet should solve.

[zezhehh]

Checks are failing because of a minor formatting issue that running go vet should solve.

Thanks! Seems it requires another approval to trigger the workflow:)

[hongalex]

One more vet issue, the exported ValidateFilter method needs a comment there.

[zezhehh]

One more vet issue, the exported ValidateFilter method needs a comment there.

Added the comment. Couldn't succeed in running vet.sh locally. Hopefully, it works this time.

[zezhehh]

Checked the error message stating that TestUpdateFilter failed due to a bad filter string. Already updated! 🙌

(However, the test TestSubscriptionMessageOrdering still fails on my computer in both the main and this branch. It seems unrelated to this PR.)

[aalobai1]

I'm so happy this is merged, thank you gcloud team ❤️