Astarte Export: Update tests for Astarte export

[osmanhadzic]

Make adjustments to the automated tests for Astarte tools as follows:

• Update the configuration to use astarte_export_test as the test realm name.
• Update the test data to include missing data types (e.g., arrays).
• Fix any broken tests identified during the changes.

Environment Setup

To run the test, ensure the following environment variables are set:

export CASSANDRA_DB_HOST="127.0.0.1"  
export CASSANDRA_DB_PORT=9042  
export CASSANDRA_NODES="localhost:9042" 

Additionally, ensure the Scylla database is running and port 9042 is exposed.

To Reproduce

• Open astarte/tools/astarte_export/test
• Run command mix test

Files

List of files potentially affected:

• astarte_export_test.exs
• database_test.exs

Tasks

• Use astarte_export_test as the default realm name.
• Add test cases for array data types.
• Fix any broken tests identified during or after the changes.
• Ensure that all existing tests pass after the changes.
• Update documentation if necessary.