Low Q2 acts surfaces

[simonge]

Briefly, what does this PR introduce?

Introduces ACTS surfaces to the Low-Q2 tracker layers. Will allow acts methods to be used in the reconstruction but should almost certainly remain separate from the main tracking reconstruction.

I am currently going around in circles so am opening a draft PR to hopefully receive some advice on where I'm going wrong. Possibly it's an entirely ill fated attempt based which will need to be scrapped.

What kind of change does this PR introduce?

• [ ] Bug fix (issue #__)
• [x] New feature (issue #__)
• [ ] Documentation update
• [ ] Other: __

Please check if this PR fulfills the following:

• [ ] Tests for the changes have been added
• [ ] Documentation has been added / updated
• [ ] Changes have been communicated to collaborators

Does this PR introduce breaking changes? What changes might users need to make to their code?

No

Does this PR change default behavior?

No