Optimize map contour lines and fix long line bug

[faern]

This PR implements the changes needed to match with mullvad/globe-mesh-builder#1. The description for this change is basically the same, so I'll copy it over:

This PR does three things to the contour lines between geographical entities:

• Subdivide long contour edges just like we do with triangles. Makes long lines not take a shortcut through earth and end up not visible
• Removed duplicate contour line segments. Keep a HashSet with seen edges and skip already drawn edges
• Order the contour line index buffer so it can be drawn as a single continuous line with GL_LINE_STRIP instead of the current GL_LINES. This reduces the size of the land_contour_indices.bin file from 873 kb bytes to 392 kb.

If we had access to OpenGL 3.1 we could draw the line strips much nicer with a single draw call thanks to glPrimitiveRestartIndex. But sadly this is not available to us. Instead this uses a hack where we continue the continuous line by drawing underneath the earths crust to the new position and pop back up there.

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This change is 

[faern]

Reviewable status: 0 of 4 files reviewed, 1 unresolved discussion

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android/lib/map/src/main/kotlin/net/mullvad/mullvadvpn/lib/map/internal/shapes/Globe.kt line 156 at r1 (raw file):

    companion object {
        private const val LAND_OCEAN_SCALE_FACTOR = 0.99999f

We can draw the land triangles closer to the contour lines now. This is because the contour lines are subdivided into shorter segments, staying closer to the sphere radius of 1.0. As such they don't go through the crust as easily and the crust can move closer!

[Rawa]

Nice work!

Reviewed 4 of 4 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion

[raksooo]

Reviewed 1 of 4 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion