Add scheduling, machine info, caching strategies and devices (#9)

Reviewed-on: Rubydragon/MetagraphOptimization.jl#9
Co-authored-by: Anton Reinhard <anton.reinhard@proton.me>
Co-committed-by: Anton Reinhard <anton.reinhard@proton.me>

src/utility.jl

@@ -87,3 +87,19 @@ Return the memory footprint of the node in Byte. Used in [`mem(graph::DAG)`](@re
 function mem(node::Node)
     return Base.summarysize(node, exclude = Union{Node, Operation})
 end
+
+"""
+    unroll_symbol_vector(vec::Vector{Symbol})
+
+Return the given vector as single String without quotation marks or brackets.
+"""
+function unroll_symbol_vector(vec::Vector)
+    result = ""
+    for s in vec
+        if (result != "")
+            result *= ", "
+        end
+        result *= "$s"
+    end
+    return result
+end