X pipeline/additional properties magic margin

[alex-vazquez]

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Purpose of this PR

Fixing the magic margin of the additional properties

URP Asset:

HDRP Light inspector

Volume Editor 1 level additional properties

Volume Editor 2 level of additional properties

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Testing status

Test URP asset, HDRP light inspector and Volume Component Editors

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Comments to reviewers

I've put the description of the problem in the comment in the code :) We are generating a new GUIStyle everytime, but I think is not a big problem

[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://yamato.cds.internal.unity3d.com/jobs/902-Graphics
Search for your PR branch using the sidebar on the left, then add the following segment(s) to the end of the URL (you may need multiple tabs depending on how many packages you change)

HDRP
/.yamato%252Fall-hdrp.yml%2523PR_HDRP_2021.2

SRP Core
You could run ABV on your branch before merging your PR, but it will start A LOT of jobs. Please be responsible about it and run it only when you feel the PR is ready:
/.yamato%252F_abv.yml%2523all_project_ci_2021.2
Be aware that any modifications to the Core package impacts everyone in the Graphics repo so please discuss the PR with your lead.

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.