Use DefaultInstance in pallet-working-team for benchmark's test to work

Since for the test function to be generated benchmarks_instance calls benchmark_iter which calls impl_benchmark_test, there when creating the function it use the following:

fn [<test_benchmark_ $name>] <T: Trait> () -> Result<(), &'static str>
				where T: frame_system::Trait, $( $where_clause )*

For this to work Trait needs a default implementation(otherwise Trait doesn't exist what exists is Trait<I>) or it would fail with the following error(compiled with -Z macro_backtrace):

error[E0107]: wrong number of type arguments: expected 1, found 0
    --> /home/conectado/.cargo/git/checkouts/substrate-7e08433d4c370a21/00768a1/frame/benchmarking/src/lib.rs:1109:37
[....] snip for redability
...
1048 | /  macro_rules! impl_benchmark_test {
1049 |        (
1050 |            { $( $where_clause:tt )* }
1051 |            NO_INSTANCE
...
1109 |                fn [<test_benchmark_ $name>] <T: Trait> () -> Result<(), &'static str>
     |                                                 ^^^^^ expected 1 type argument
...
1152 |        };
1153 | |  }
     | |__- in this expansion of `$crate::impl_benchmark_test!` (#4)
     | 
    ::: runtime-modules/working-team/src/benchmarking.rs:225:1
     |
225  | /  benchmarks_instance! {
226  | |      _ { }
227  | |
228  | |      /*
...    |
581  | |      verify { assert_eq!(true, true); }
582  | |  }
     | |__- in this macro invocation (#1)

error: aborting due to previous error

What is need to be done is:

• Change in decl_storage here the definition of the Store for:

    trait Store for Module<T: Trait<I>, I: Instance=DefaultInstance> as WorkingTeam {

• Change decl_module and the declaration of the Trait accordingly
• Change implement Trait instead of Trait<TestWorkingTeamInstance> for Test here because for the verify tests we use Test

Update runtime-modules/working-team/src/lib.rs so the storage, module, and Trait declarations use DefaultInstance, then adjust runtime-modules/working-team/src/tests/mock.rs to implement Trait for Test. Start by reviewing the benchmarks_instance! usage in runtime-modules/working-team/src/benchmarking.rs and the linked benchmarking macro definitions. Done means the generated benchmark test compiles and the verify tests using Test pass.