eth/tracers: report correct gasLimit in call tracers (#27029)

This includes a semantic change to the `callTracer` as well as `flatCallTracer`.
The value of field `gas` in the **first** call frame will change as follows:

- It previously contained gas available after initial deductions (i.e. tx costs)
- It will now contain the full tx gasLimit value

Signed-off-by: jsvisa <delweng@gmail.com>

eth/tracers/native/call.go

@@ -133,7 +133,7 @@ func (t *callTracer) CaptureStart(env *vm.EVM, from common.Address, to common.Ad
 		From:  from,
 		To:    &toCopy,
 		Input: common.CopyBytes(input),
-		Gas:   gas,
+		Gas:   t.gasLimit,
 		Value: value,
 	}
 	if create {