Implement TuneMonitor

[gubaidulinvadim]

Same ideas as for BPMs and RF devices for implementation. For functionality, see:
User interface specification document

2.2.7 Tune monitors
Betatron tune monitor
A BetatronTune handle measurement of betatron tune and inherits from Element. For the beta-
tron tune adjustment, the tune response matrix is referenced in the configuration file (it can be
either obtained from measurement or from design). Tune monitor configuration (‘tune monitor.yml’)
should be flexible and allow to define several different tune monitors originating from different hard-
ware/measurement method and use different response matrices. A standard object name (for example,
‘tune monitor’) of the class BetatronTune will be used to define which monitor will be used in common
high-level applications. The way the tune is set, for example which quadrupole family is used, is also
defined in the configuration file.
h: ReadWriteScalar gets/sets the horizontal tune.
v: ReadWriteScalar gets/sets the vertical tune.
update_optics() if not available, computes tuneRM based on design and stores it the ML data
folder.
Longitudinal tune monitor
Similarly to the BetatronTune, A LongitudinalTune can be defined to measure the longitudinal tune.
l: ReadWriteScalar gets/sets the longitudinal tune.
update_optics() if not available, computes tuneRM based on design and stores it the ML data
folder.
Combined tune monitor
The betatron tune monitor and longitudinal tune monitor can be combined into one ElementArray
for the machines who want to measure all three components at the same time. In case the slowest
measurement will give the rate of the array.