feat(bindings/java): convey backtrace on exception

[tisonkun]

I'm not sure if it's better to expose a method said display(force_backtrace: bool) in opendal::Error.

Without backtrace, it's very hard to debug across binding (language) boundary.

Before -

org.apache.camel.FailedToCreateRouteException: Failed to create route route1: Route(route1)[From[opendal://foo] -> [To[opendal://bar], To[... because of Failed to resolve endpoint: opendal://foo due to: Unexpected (permanent) at  => Null pointer in get_object_class, source: Null pointer in get_object_class

	at org.apache.camel.reifier.RouteReifier.createRoute(RouteReifier.java:82)
	at org.apache.camel.impl.DefaultModelReifierFactory.createRoute(DefaultModelReifierFactory.java:49)

After with RUST_BACKTRACE=1 -

[ERROR] Tests run: 2, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.479 s <<< FAILURE! -- in org.apache.opendal.test.OperatorInfoTest
[ERROR] org.apache.opendal.test.OperatorInfoTest.testOperatorInfo -- Time elapsed: 0.036 s <<< ERROR!
org.apache.opendal.OpenDALException: 
Unexpected (permanent) at  => Null pointer in get_string obj argument, source: Null pointer in get_string obj argument
Backtrace:
   0: std::backtrace_rs::backtrace::libunwind::trace
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1: std::backtrace_rs::backtrace::trace_unsynchronized
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2: std::backtrace::Backtrace::create
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/std/src/backtrace.rs:332:13
   3: opendal_java::error::Error::new
             at ./src/error.rs:38:24
   4: opendal_java::error::Error::unexpected
             at ./src/error.rs:43:9
   5: <opendal_java::error::Error as core::convert::From<jni::wrapper::errors::Error>>::from
             at ./src/error.rs:103:9
   6: <core::result::Result<T,F> as core::ops::try_trait::FromResidual<core::result::Result<core::convert::Infallible,E>>>::from_residual
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/core/src/result.rs:1961:27
   7: opendal_java::jstring_to_string
             at ./src/lib.rs:230:24
   8: opendal_java::operator::intern_constructor
             at ./src/operator.rs:56:35
   9: Java_org_apache_opendal_Operator_constructor
             at ./src/operator.rs:49:5


	at org.apache.opendal.Operator.constructor(Native Method)
	at org.apache.opendal.Operator.of(Operator.java:115)

[tisonkun]

Updated.

[Xuanwo]

Thanks!