fix(recordings): use a helpful error messge for http-based targets

[tthvo]

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Temporary fixes for #944

Description of the change:

Use a special error message for http-based targets.

Motivation for the change:

See #944

How to manually test:

1. Run CRYOSTAT_IMAGE=quay.io... sh smoketest.sh...
2. Go to Recording tab -> Create Recording -> Select 9988 (http).
3. See the error message.

Screenshots

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[tthvo]

I suppose even when Automated Rule is enabled that matches these targets, no recordings will be created anyway?

[github-actions]

Test image available:

CRYOSTAT_IMAGE=ghcr.io/cryostatio/cryostat-web:pr-954-f9842057b3c2c1d181e770333d5660e0b2723ef7 sh smoketest.sh

[andrewazores]

I suppose even when Automated Rule is enabled that matches these targets, no recordings will be created anyway?

Right, it will just fail silently in the background since there will be a server-side exception when it tries to perform the action. Similar to what should happen when creating or activating a rule that matches a target that requires credentials, and there are no valid stored credentials.

[tthvo]

Make sense thanks!