feat(test-tooling): flag to omit contract deployment in Fabric AIO container

[petermetz]

Description

As a developer I want to be able to use the Fabric AIO container for rapid prototyping so that I'm more productive while working on a chain code contract with Cactus.

Right now the Fabric AIO container always goes through the deployment of the default basic asset transfer contract which takes time before the health check starts passing.

What we could do is add an environment variable that the container checks for and based on that it omits the deployment of the default contract to speed things up.

Acceptance Criteria

1. Flag to control whether the deployment of the default contract happens or not.
2. At least one test verifying the working of the flag
3. The container health check is updated so that it does not rely on the default contract anymore where not applicable (e.g. if the flag from 1) was set)
4. Health check must still be a reliable indicator of the ledger being up and running otherwise we'll have a bunch of flaky tests on our hands right after merging this change.

cc: @takeutak @sfuji822 @hartm @jonathan-m-hamilton @AzaharaC @jordigiam @kikoncuo @petermetz @arnab-roy