Add ability to disable/set depth limit

[MarshalX]

Hello! cbor4ii's decoder comes with deep limit which could be disabled/increased by implementing own dec::Read. But serde_ipld_dagcbor implements it's own including deep limit. So I'm wondering is there any simple way to disable/increase it? For now i just copied de.rs to my codebase which is not pretty

I use serde_ipld_dagcbor like this:

serde_ipld_dagcbor/src/lib.rs

Lines 69 to 78 in ffae329

	//! Read a general CBOR value with an unknown content.
	//!
	//! ```rust
	//! use serde_ipld_dagcbor::from_slice;
	//! use libipld_core::ipld::Ipld;
	//!
	//! let slice = b"\x82\x01\xa1aaab";
	//! let value: Ipld = from_slice(slice).unwrap();
	//! println!("{:?}", value); // List([Integer(1), Map({"a": String("b")})])
	//! ```

upd. as i understand serde_ipld_dagcbor doesn't tune depth limit at all. so the default (256) comes from cbor4ii. which is too small for me

[vmx]

@MarshalX would it help if the Deserializer would be public? I think then you could implement it for your own reader with your own limits.

[vmx]

@MarshalX In the most recent release is the Deserializer public. Did you have have chance to see if setting the depth limit now works for you?

[MarshalX]

hi @vmx and thank you for your effort! i'm a bit busy these days but i'll try to verify as soon as i can. sorry for the long response