Logging inside WASM module

[Joffref]

Expected Behavior

Logging inside WASM module should be exposed to the user instead of panicking.

Actual Behavior

When an error occurs, the WASM module panic and exposes an error like this:

engine_test.go:44: wasm error: unreachable
        wasm stack trace:
        	.rust_panic()
        		0x1dd9d7: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/panic_abort/src/lib.rs:83:17 (inlined)
        		          /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/panic_abort/src/lib.rs:37:5 (inlined)
        		          /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:744:9
        	._ZN3std9panicking20rust_panic_with_hook17h7f7102b82d51338fE(i32)
        		0xc7c1d: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:714:5
        	._ZN3std9panicking19begin_panic_handler28_$u7b$$u7b$closure$u7d$$u7d$17hfa40135feb109919E(i32)
        		0x1dda27: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:583:13
        	._ZN3std10sys_common9backtrace26__rust_end_short_backtrace17haf21bfec9a028e09E(i32)
        		0x1dd9de: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/sys_common/backtrace.rs:150:18
        	.rust_begin_unwind(i32)
        		0x185760: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/std/src/panicking.rs:579:5
        	._ZN4core9panicking9panic_fmt17he4489d678d6570d5E(i32,i32)
        		0x320: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/core/src/panicking.rs:64:14
        	._ZN4core6result13unwrap_failed17h9c69c0d7a98df92bE(i32,i32,i32,i32,i32)
        		0x2dee8: /rustc/84c898d65adf2f39a5a98507f1fe0ce10a2b8dbc/library/core/src/result.rs:1750:5
        	.is_authorized(i32,i32,i32,i32,i32,i32,i32,i32) i64
      ```