chore(esplora): updated `esplora` tests to use `TestEnv` #9

Job	Run time
Check no_std	49s
clippy_check	5m 53s
Build and test (stable, true, --no-default-features)	1m 16s
Check WASM	1m 18s
Build and test (stable, true, --all-features)	1m 15s
Rust fmt	19s
Build and test (1.57.0, --no-default-features)	57s
Build and test (1.57.0, --all-features)	1m 7s
	12m 54s

Provide feedback