feat: migrate from Akka to JAVA virtual threads based tasks

[raits]

This PR does the following:

• Migrates from Akka actors to JAVA virtual thread based tasks using blocking queue to communicate and semaphores to enforce concurrent tasks as they were for actors
• Ports tests from actors to tasks and fixes them so that they hide errors less (though there might still be some cases, as the logic behind the actors was changed as little as possible to minimize side-effects)
• The XRoadClient will be revisited once we have updated XRD4J, because the current one is used in a potentially non-threadsafe way
• The FI profile tasks for companies and organizations mimics the behavior in the actor model, but it will be changed in a follow-up task since the original implementation seems flawed
• Configuration defaults were included in JAVA annotations where sensible to minimize risk of a misconfiguration causing the service not to start
• Added a check at startup, which verifies that the keystore exists on the given path before trying to use it as it caused issues when it didn't exist

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅

[petkivim]

Here "actor" should be replaced with "thread" or remove the comment since it may not apply to the new implementation anymore.

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.3% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

Job Summary for Gradle

X-Road-Catalog tests :: BuildAndTest

Gradle Root Project	Requested Tasks	Gradle Version	Build Outcome	Build Scan®
x-road-catalog	build test	8.7	✅