Case for TP4056 lithium charger with strain relief

Added strain relief feature to the original design. The case is longer to accommodate zip-tie, but it's pretty minimal (4mm longer). Need re-orientation, but can print without any supports.

Printing filament: Original designer called for more heat-resistant filament, but I've used the case in PLA for months without any issue perhaps thanks to designed air gaps.

Model selection: Use “large exit” version if you have 4 wires comming out and the standard version for 2 wires. (I used 24awg, but anything smaller than 20awg should work.)