Filament unload/load on long bowden cause error in the generated gcodes

[thephantom1492]

Describe the bug
[Un]Loading the filament with a very long bowden cause the generated gcode to be wrong, issuing a mix of relative and absolute move instead of all relative move, causing the filament to reverse direction constantly.

To Reproduce
Steps to reproduce the behavior:

1. Go to the settings and set to: feed length: 1990, Purge distance: 30mm, Feed speed: 30 mm/s, feed speed slow: 5mm/s
2. Change filament (I used the spool manager to select a new spool)
3. Watch as the filament unload, load, unload, load multiple time
4. See error

Expected behavior
A normal unload/load

Screenshots
No screenshot but see bellow for the gcode.

General Information:

• Hardware RPI 4B 8G
• OS Info: Octoprint 1.10.1, Python 3.9.2, Octopi 1.0.0, Octodash 2.3.1

Additional context
Generated unload gcode:
M104 S200
G91
G91
G91
M83
G91
G91
M83
M83
M83
G1 E-100 F1800
M82
G91
M83
G1 E-100 F1800
G1 E-100 F1800
G90
M83
G1 E-100 F1800
M82
M82
M82
G1 E-100 F1800
G1 E-100 F1800
M82
G90
G90
M82
G90
G91
M83
G90
G90
G1 E-100 F1800
M82
G90
G91
M83
G1 E-100 F1800
M82
G90
G91
M83
G1 E-100 F1800
M82
G90
G91
M83
G91
G91
G1 E-100 F1800
M83
G1 E-100 F1800
M82
M82
G90
M83
G91
G90
G91
M83
G1 E-100 F1800
M82
G1 E-100 F1800
M83
G1 E-100 F1800
G90
M82
G91
M82
G90
M83
G90
G1 E-100 F1800
G91
M82
M83
G90
G1 E-100 F1800
M82
G90
G91
M83
G1 E-100 F1800
M82
G90
G91
M83
G1 E-100 F1800
G91
M82
G90
G91
M83
G1 E-90 F1800
M83
M82
G90
G1 E-100 F1800
M82
G90
M18 E