Deprecations for the next major release

mockolo has a long history and includes some features that are not widely known.
With the advancements in Swift, some of these features are now likely impractical or obsolete, yet they are still being maintained.
Some features also require a lot of effort to keep working.

Currently, we do not have enough people or time to maintain mockolo, and we are struggling to keep up with the latest features in Swift.
Therefore, for the next major update, we would like to deprecate some old or undocumented features that seem to be unused.

The features scheduled for removal are as follows:

• --allow-set-call-count flag
  This will always be treated as true. There shouldn't be any cases where this causes issues.
• --use-template-func flag
  Is anyone actually using this? It is not well tested, and there may be many situations where it doesn’t work properly. Furthermore, in modern Swift there are alternative approaches such as function body macros.
• Parent mock feature
  This is an undocumented, hidden feature with very complex behavior. In short, it allows you to provide part of the mock class implementation from existing source code. While it is a unique feature, I don’t believe anyone is using it.

Deprecation Plan

First, we display a warning in the console when these features are used. Afterwards, unless there are strong objections, we will proceed to remove these features.

Start by tracing handling for the --allow-set-call-count and --use-template-func flags, then locate the undocumented parent mock feature. Review how each feature is currently used and how console warnings are emitted. Done means the deprecation plan is implemented for all three features and their warning behavior is verified.