Disables direct recursion on templates by default

[kiranandcode]

Fixes #447
On the meeting on Tuesday we discussed a few solutions, I believe this was the one we agreed would be the minimal fix?

#447 (comment)

Adds optional parameter recursive (default value is False) to Template.define and field is_recursive to Templates.

When constructing tools, if the Template is not recursive, then it removes itself from the tuple of tools.

This restores previous functionality, and in cases where users require direct recursive calls, they can call Template.define(recursive=True)

[eb8680]

Rather than adding a recursive parameter to Template.define, can we expose this behavior via a special effectful.ops.types.Annotation that is applied to a return type and could in principle desugar to a more verbose but equivalent effect type, even if it's not (yet?) implemented that way?

class _IsRecursiveAnnotation(effectful.ops.types.Annotation): ...

IsRecursive = _IsRecursiveAnnotation()

...

@Tool.define
def search_web(query: str) -> str: ...

@Template.define
def research(topic: str) -> typing.Annotated[str, IsRecursive]: ...

[eb8680]

Also needs to be updated following #424

[kiranandcode]

Rather than adding a recursive parameter to Template.define, can we expose this behavior via a special effectful.ops.types.Annotation that is applied to a return type and could in principle desugar to a more verbose but equivalent effect type, even if it's not (yet?) implemented that way?

class _IsRecursiveAnnotation(effectful.ops.types.Annotation): ...

IsRecursive = _IsRecursiveAnnotation()

...

@Tool.define
def search_web(query: str) -> str: ...

@Template.define
def research(topic: str) -> typing.Annotated[str, IsRecursive]: ...

gotcha, can do!

Also needs to be updated following #424

gotcha! rebasing.

[kiranandcode]

Done!

[eb8680]

Thanks, just a couple nits