fix premature exit of 'sylvactl watch' on transient HelmRelease errors

Related to #1849 (closed)

This MR is a short-term expedient for #1849 (closed) : we override --exit-condition of sylvactl watch commands to not use all of the builtin ones.

The built-in ones are (here):

			map[string]string{"message": "values don't meet the specifications of the schema"},
			map[string]string{"message": "install retries exhausted"},
			map[string]string{"message": ": execution error at "},

We only keep the "values don't meet the specifications of the schema" one.

To address #1849 (closed) at short term, we don't keep execution error at because in some cases we don't want sylvactl to fail on this.

See the discussion in #1849 (closed) to see what can be a better long-term solutio.

(also, in this MR install retries exhausted isn't kept, because we now have introduced automatic retries to cover that case, we don't want to fail on this case)