Add a `-d` | `--depth` flag for traces (like verbose forge tests)

[Mouradif]

Component

Forge

Describe the feature you would like

When I find myself running failing tests with traces (-vvv), I very often would like to set a depth limit to the traces I get. Especially when I am fork-testing and I only want to debug the part that goes up to one level after external calls made by my contracts.

The idea is to turn a trace like

$ forge test -vvv
[FAIL: SomethingAintRight()] test_MyTest() (gas: 6666666)
Traces:
  [6666666] MyContractForkTest::test_MyTest()
    ├─ [25350] MyContract::myMethod(true, 123))
    │   ├─ emit Event()
    │   └─ ← [Return] true
    │   ├─ [90993] MyOtherContract::someMethod(456, false)
    │   │   ├─ [75592] SomeDeployedContractInMyForkTest::itsOwnMethod() [staticcall]
    │   │   │   ├─ [60284] TheImplementationOfThatContract::itsOwnMethod() [delegatecall]
    │   │   │   │   ├─ [2603] SomeOtherDeployedContract::blablabla() [staticcall]
    │   │   │   │   │   └─ ← [Return] 0x0000000000000000000000000000000000000000000000000000000000000001
    │   │   │   │   ├─ [2681] AndYetAnotherDeployedContract::youGetTheGist() [staticcall]
    │   │   │   │   │   └─ ← [Return] 0x0000000000000000000000000000000000000000000000000000000000000002
    │   │   │   │   └─ ← [Return] 1, 2
    │   │   │   └─ ← [Return] false
    │   |   └─ ← [Revert] SomethingAintRight()
    |   └─ ← [Revert] SomethingAintRight()
    └─ ← [Revert] Transfer failed

Into:

$ forge test -vvv -d 3 # or --depth 3
[FAIL: SomethingAintRight()] test_MyTest() (gas: 6666666)
Traces:
  [6666666] MyContractForkTest::test_MyTest()
    ├─ [25350] MyContract::myMethod(true, 123))
    │   ├─ emit Event()
    │   └─ ← [Return] true
    │   ├─ [90993] MyOtherContract::someMethod(456, false)
    │   │   ├─ [75592] SomeDeployedContractInMyForkTest::itsOwnMethod() [staticcall]
    │   │   │   └─ ← [Return] false
    │   |   └─ ← [Revert] SomethingAintRight()
    |   └─ ← [Revert] SomethingAintRight()
    └─ ← [Revert] Transfer failed

Now obviously, this example is small but I think it illustrate the point. Otherwise, happy to show a real life example if that helps.

Additional context

I put the component forge in the dropdown but it would also apply for cast run