Extend mrd for reconstruction

[ckolbPTB]

Here are a few changes which are needed to ensure reconstruction is possible with MRpro. We are using this here to validate our Pulseq sequences:
Code: https://github.com/PTB-MR/mrseq/blob/main/examples/t2_multi_echo_se_single_line.ipynb
Rendered output: https://ptb-mr.github.io/mrseq/t2_multi_echo_se_single_line.html

Main changes:

• add resonance frequency which is a required field for ISMRMRD
• ensure values from Pulseq (in s) are translated to ms for ISMRMRD
• each acquisition should have orientation information, although we do not know it we give it something reasonable
• NOISE samples are detected - here it would be great if noise could be added as simulated in MRzero, not sure if this information is available at this stage

Further things which would be nice (but I don't know how to do it):

• get the FOV and matrix sizes correctly from MRzero
• get a timestamp for each acquisition from MRzero (done in 8942945)

Any suggestions or further improvements very welcome!

[J-Endres]

Thank you for the additions!
There is a possibility of an crash if FOV is not set, otherwise I'm happy to merge the changes.

resolved