Add minFilter and magFilter to material component replacing npot

[mrxz]

Description:
As discussed in #5706 the npot property was only intended for working with non-power-of-two textures in WebGL 1. It's being used in several places to indirectly set the minFilter to THREE.LinearFiltering. This PR introduces minFilter and magFilter properties allowing the filtering methods to be set directly and explicitly.

Changes proposed:

• Add minFilter and magFilter properties to material component to set texture filtering.
• Remove npot property from material component

[dmarcos]

PR ended pretty big

[mrxz]

PR ended pretty big

Not really? The majority is the auto-generated attribute tables for primitives in the docs. Kind of unavoidable when material properties change.

The actual changes are minimal: npot out and mag/minFilter in:

 docs/components/material.md                       |  3 ++-
 src/components/layer.js                           |  2 +-
 src/components/material.js                        |  6 +++++-
 src/extras/primitives/primitives/a-sky.js         |  2 +-
 src/extras/primitives/primitives/a-videosphere.js |  2 +-
 src/utils/material.js                             | 23 +++++++++++------------
 6 files changed, 21 insertions(+), 17 deletions(-)

[vincentfretin]

I verified with some console.log that by default on a texture we have

wrapS = THREE.ClampToEdgeWrapping;
wrapT = THREE.ClampToEdgeWrapping;
magFilter = THREE.LinearFilter;
minFilter = THREE.LinearMipmapLinearFilter;

so here the default on the minFilter and magFilter properties in this PR matches that and just setting minFilter to linear indeed does the same thing than the previous code.

Also I confirm this is still needed to set minFilter here.
I don't see any difference between minFilter LinearMipmapLinearFilter and LinearFilter on a 4096x2048 image on Quest 3
https://github.com/aframevr/aframe/blob/master/examples/boilerplate/panorama/puydesancy.jpg
but I see a difference in sharpness on a 8192x4096 image with a bit of flickering at times
https://github.com/c-frame/aframe-stereo-component/blob/master/examples/basic_image/textures/L.jpg
Of course it's even better with a mono equirect layer and there is no flickering at all.

So the changes in the PR looks good to me. Thanks for the work @mrxz
If some third party components used npot: true, it will need to be updated to use minFilter: linear instead.

[dmarcos]

Thanks!