[azure-pipeline] parametrized pipeline

[Raffaello]

[...] so can be completely independent, also because there is no relation among them, or at least not too much.

• [x] use parameters
• [x] template the jobs (mac, linux are the same almost ever, just differencing in naming)
• [ ] so it can be easily divided in a "build matrix".
• [ ] each OS with its own badge too.
• [x] create a folder for store the yml files instead of putting in the root...
• [ ] it might be easier to store artifacts.
• [x] related to #62
• [x] adjust #62 to reflect the new "pipelines config"
• [x] depends on #94 (update appveyor ignore files here)

[Raffaello]

splitting the 1 os pipeline here: #96