feat: add `recent_first` alternative sorting arg to `ImmudbClient.history()` method

[NickAnderegg]

The current argument sortorder in ImmudbClient.history() is unclear from its name. Making it more confusing, it's the opposite of the typical Python convention for sort orders, where a boolean affecting sort order is typically False by default, e.g.:

sorted(iterable, /, *, key=None, reverse=False)

This change adds a new argument, recent_first, which has the same functionality as sortorder, but doesn't require reading the docs to understand what it means. I've implemented recent_first as a keyword-only argument and redefined sortorder as an optional positional-or-keyword argument.

This means that existing applications that call this method will be unaffected, but has the added advantage of still working as expected if someone gets confused about the argument names in the future. I've written it so that all of these calls would function identically:

client.history(key, offset, limit, True)
client.history(key, offset, limit, sortorder=True)
client.history(key, offset, limit, recent_first=True)
client.history(key, offset, limit, True, recent_first=True) # recent_first is ignored when sortorder is specified
client.history(key, offset, limit, sortorder=True, recent_first=True)
client.history(key, offset, limit, sortorder=True, recent_first=False)  # recent_first is ignored when sortorder is specified
client.history(key, offset, limit, sortorder=True, recent_first="xyz")  # recent_first is ignored when sortorder is specified

Because effectively specifying yes or no when the method asks what is our sort order? is very confusing!