TxGraph<A> should be able to transform anchor types.

[evanlinjin]

Describe the enhancement

impl<A1, A2: From<A1>> From<TxGraph<A1>> for TxGraph<A2> {
    // TODO
}

If A2: From<A1> is impossible, we can have a method:

impl<A> TxGraph<A> {
    pub fn map_anchors<A2, F>(self, f: F) -> TxGraph<A2> where F: Fn(A) -> A2 { todo!() }
}

Use case

Some chain source methods return TxGraphs. It will be good to update original TxGraphs with different anchor types.

[LLFourn]

Same as #1096 I think. I closed it since we didn't have a concrete situation to do this. Do we have one now?

[evanlinjin]

@LLFourn I think we need this. There were a couple of times I was like "this functionality would be nice". Otherwise I've been recreating a TxGraph by getting an initial changeset and working from there.

[yanganto]

I want to try this. 😄

[evanlinjin]

I want to try this. 😄

Go for it!