Including a list of available allocators when allocator not found

[kab163]

Error message now includes list of available allocators:

terminate called after throwing an instance of 'umpire::runtime_error'
  what():  ! Umpire runtime_error [/g/g0/belcher6/Umpire/src/umpire/ResourceManager.cpp:205]: Allocator "BANANAS" not found. Available allocators: HOST FILE DEVICE DEVICE::FINE DEVICE::COARSE DEVICE::0 DEVICE::0::FINE DEVICE::0::COARSE DEVICE::1 DEVICE::1::FINE DEVICE::1::COARSE DEVICE::2 DEVICE::2::FINE DEVICE::2::COARSE DEVICE::3 DEVICE::3::FINE DEVICE::3::COARSE UM UM::FINE UM::COARSE PINNED PINNED::FINE PINNED::COARSE 
    Backtrace: 10 frames
    0 0x3b1244 No dladdr: ./bin/allocator() [0x3b1244]
    1 0x3b3e95 No dladdr: ./bin/allocator(_ZN6umpire4util10backtracerINS0_12trace_alwaysEE13get_backtraceERNS0_9backtraceE+0x15) [0x3b3e95]
    2 0x3b3a7b No dladdr: ./bin/allocator(_ZNK6umpire13runtime_error7messageB5cxx11Ev+0x4b) [0x3b3a7b]
    3 0x3b3274 No dladdr: ./bin/allocator(_ZN6umpire13runtime_errorC2ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEES8_i+0x84) [0x3b3274]
    4 0x3df287 No dladdr: ./bin/allocator(_ZN6umpire15ResourceManager21getAllocationStrategyERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x4b7) [0x3df287]
    5 0x3df8e4 No dladdr: ./bin/allocator(_ZN6umpire15ResourceManager12getAllocatorERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x1f4) [0x3df8e4]
    6 0x3df963 No dladdr: ./bin/allocator(_ZN6umpire15ResourceManager12getAllocatorEPKc+0x53) [0x3df963]
    7 0x3b0f79 No dladdr: ./bin/allocator(main+0xc9) [0x3b0f79]
    8 0x155552af4865 No dladdr: /lib64/libc.so.6(__libc_start_main+0xe5) [0x155552af4865]
    9 0x3b0e0e No dladdr: ./bin/allocator(_start+0x2e) [0x3b0e0e]


Aborted (core dumped)

[kab163]

We will actually combine the 2 lists and then output it in a more readable way. This PR is converted back to draft for now