Export `FlowGraph::AbortIfRequested`

[emesare]

We allow users to implement their own flow graph layout providers and we allow users to request flow graph layouts (positioning of nodes within a flow graph). The issue is that we do not allow for flow graph layout providers to be cancelled/aborted, we export FlowGraphLayoutRequest::Abort() but no way to check if the request has been aborted.

binaryninja-api/binaryninjaapi.h

Line 13339 in ba13f6e

void Abort();

binaryninja-api/binaryninjaapi.h

Line 13605 in ba13f6e

virtual bool Layout(Ref<FlowGraph> graph, std::vector<Ref<FlowGraphNode>>& nodes);

We have this internally, a function called AbortIfRequested. It might be beneficial to also understand the internals of that function before trying to expose it, seeing as it also forces flags other than the "is aborted" flag.