Feature/line seg map multiplebucket

[xbuffat]

Description

Implementation of a limited bucket length for the linear RF model. The kick corresponds to a sawtooth giving linear focusing around each fixed points in order to simulate multiple bunches keeping the linear RF approx.

Closes # .

Checklist

Mandatory:

• [x] I have added tests to cover my changes
• [ ] All the tests are passing, including my new ones
• [ ] I described my changes in this PR description

Optional:

• [ ] The code I wrote follows good style practices (see PEP 8 and PEP 20).
• [ ] I have updated the docs in relation to my changes, if applicable
• [ ] I have tested also GPU contexts