Enables per node includes on the DecalPass.template

[Jonasmortensen]

This line is also in the ShaderPass.template used by the other URP targets.

Without it, custom function nodes referencing a file cannot be used with the decal target.
The PR also fixes procedural shadergraph nodes (like simple noise) not compiling when used with the decal target. Reason being that the required include was not being included.

[github-actions]

Hi! This comment will help you figure out which jobs to run before merging your PR. The suggestions are dynamic based on what files you have changed.
Link to Yamato: https://unity-ci.cds.internal.unity3d.com/project/902/
Search for your PR branch using the search bar at the top, then add the following segment(s) to the end of the URL (you may need multiple tabs depending on how many packages you change)

URP
/jobDefinition/.yamato%252Fall-urp.yml%2523PR_URP_trunk
With changes to URP packages, you should also run
/jobDefinition/.yamato%2Fall-lightmapping.yml%23PR_Lightmapping_trunk

Depending on the scope of your PR, you may need to run more jobs than what has been suggested. Please speak to your lead or a Graphics SDET (#devs-graphics-automation) if you are unsure.