explorerd/test_utils: add initial test data with preloaded native smart contracts

Adds an initial test data into a `explorerd` sled database with preloaded native smart contracts to the `test_utils` module. This test data will be updated over time, but currently optimizes testing by eliminating the need to load smart contracts for every test run.

bin/explorer/explorerd/src/test_utils/test_data/explorerd_0/conf

@@ -0,0 +1,4 @@
+segment_size: 524288
+use_compression: false
+version: 0.34
+vQÁ