Fix xml validation problems

[fballiano]

We're trying to introduce XML validation as a github workflow, the commonly used technique is running xmllit with something like:

find . -type f -iname '*.xml' | xargs -I '{}' xmllint --noout '{}'

problem is, xmllint is broken because our XMLs have a "name" variable in some places.

Since that variable was always replaced with "Magento" I figured to:

• change the Magento name in OpenMage
• hardcode the OpenMage name in the XMLs so that xmllint works without problems

Fixed Issues (if relevant)

This PR is part of the fix for #1918

Manual testing scenarios (*)

You've the command line in the task description.
Also check that APIs work.

[fballiano]

@kiatng I think I commited all your suggestions, thanks!

merged suggestions

[addison74]

If a value cannot be assigned to {{var wsdl.name}} then this manual change is absolutely necessary.

[github-actions]

Unit Test Results

1 files  ±0  1 suites  ±0   0s ⏱️ ±0s
0 tests ±0  0 ✔️ ±0  0 💤 ±0  0 ❌ ±0 
7 runs  ±0  5 ✔️ ±0  2 💤 ±0  0 ❌ ±0 

Results for commit 4af8207. ± Comparison against base commit 0c0eef8.

[Flyingmana]

note: changing the schema name to OpenMage was breaking Integrations with external services (reported on a different place, for example here #2539 (comment))