layers: MR139, draw_state VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT checks

layers: MR139, draw_state VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT checks

Added a set to track which secondary cmdBuffers are contained within a primary cmdBuffer.
Added new DRAWSTATE_INVALID_CB_SIMULTANEOUS_USE enum value for new error/warning
cases, along with line in documentation.
New validation issues and state updates are listed below.

While tracking cmdBuffers at QueueSubmit time:
 1. Flag an error if a cmdBuffer is already in flight and does not have
    VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT set
 2. Account for tracking of secondary cmdBuffers (and their in_use resources)
    that are submitted within a primary command buffer

When submitting secondary command buffers into primary command buffer at
    CmdExecuteCommands time:
 1. Flag an error if secondary cmdBuffer is in flight and doesn't have
 VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT set.
 2. Warn user if secondary cmdBuffer doesn't have
 VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT set but primary cmdBuffer does.
 This causes primary cmdBuffer to be treated as if
 VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT isn't set.
 3. Add secondary cmdBuffers to set off of primary cmdBuffer for tracking purposes
 4. Add secondary cmdBuffers to inFlight set