Add option to visualize the depth of a well in the 3D view

[lasserenli]

Add option to visualize the measured depth of a well in the 3D view every n'th meter with n selected by the user

Suggested improvements to the first prototype

• add support for major/minor tickmarks along well path
• show the exact location of MD on the well path geometry
• avoid filled background, show text only

[magnesj]

Suggested user interface and display of labels