Fix or remove port_bound_components_report_ready and all_metrics_from_1_5_are_present tests after merge of #4280

[#4280](https://app.zenhub.com/workspaces/core-protocol-60953fafb1945f0011a3592d/issues/gh/casper-network/casper-node/4280) changed and/or removed TestChain, on which new tests added in feat-1.6 depended, which in turn have now been disabled during the merge of dev into said branch.

The `all_metrics_from_1_5_are_present` test was added on the `feat-1.6` branch, it automatically ensures that no metrics are lost by comparing against a fixed of metrics that are known to be present in 1.5. For this test to be written, a change was made to the testing framework and port bound components was made, to allow their readiness to be waited upon by a test. As an example, to retrieve metrics, the built-in HTTP server that serves them needs to be ready first.

The `port_bound_components_report_ready` test exercises this functionality, i.e. the waiting-for-readiness of specific components.

During the development of the `feat-1.6` branch, the `TestChain` refactoring (as mentioned above) caused some of this functionality to break, as a result, some of the testing code is disabled. Whether the backwards-compatibility test is kept at all or not is still up for debase. Post 1.6 or 2.0 both of these tests need to be looked at, and either restored by making them work with the new structure, or removed.