All devices should have `__repr__` method summary strings

[kabanaty]

When inspecting individual Device objects or sets of Device objects, they fill the terminal with pyepics nonsense. By including a __repr__ method, pertinent user information can be displayed cleanly.

Example:

>>> from slac_devices.reader import create_magnet
>>> QVM2 = create_magnet(name="QVM2", area="LTUH")
>>> QVM2
Magnet(name='QVM2', controls_information=MagnetControlInformation(control_name='QUAD:LTUH:120', PVs=MagnetPVSet(bctrl=<PV 'QUAD:LTUH:120:BCTRL', count=1, type=time_double, access=read/write>, bact=<PV 'QUAD:LTUH:120:BACT', count=1, type=time_double, access=read/write>, bdes=<PV 'QUAD:LTUH:120:BDES', count=1, type=time_double, access=read/write>, bcon=<PV 'QUAD:LTUH:120:BCON', count=1, type=time_double, access=read/write>, ctrl=<PV 'QUAD:LTUH:120:CTRL', count=1, type=time_enum, access=read/write>, bmin=<PV 'QUAD:LTUH:120:BMIN', count=1, type=time_double, access=read/write>, bmax=<PV 'QUAD:LTUH:120:BMAX', count=1, type=time_double, access=read/write>)), metadata=MagnetMetadata(area='LTUH', beam_path=['CU_HTXI', 'CU_HXR', 'CU_HXTES', 'CU_SFTH', 'SC_HXR'], sum_l_meters=1211.288, type='QUAD', safe_level=None, read_tolerance=None, hardware=None, l_eff=0.461, b_tolerance=None))
>>> 

Desired behavior:

>>> from slac_devices.reader import create_wire
>>> WS28144 = create_wire(name="WS28144", area="L3")
>>> WS28144
Wire(name='WS28144', area='L3', planes=X[32000-36000], Y[41000-44000], U[18000-22000])
>>>