[Templating] Allows "template" and "parameters" as parameter name (replaces #7908)
merged branch GromNaN/templating-var (PR #7951)

This PR was squashed before being merged into the master branch (closes #7951).

Discussion
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[Templating] Allows "template" and "parameters" as parameter name (replaces #7908)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT
| Doc PR        | n/a

Allows "template" and "parameters" as parameter name.
**BC break:** These variables were previously declared on every template with respectively the Templating\Storage instance and the array of parameters.

Commits
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6e8b918 [Templating] Allows "template" and "parameters" as parameter name (replaces #7908)