Fix quality and dimensions of device images used in the app

[yanascz]

We've already tweaked the existing images in https://github.com/trezor/trezor-suite/pull/14946/files#diff-813dd60bf71a0234e5f2845f8a930bad91e3df4f086e75165aeabc659b3b810f. However, it was just a quick & dirty solution.

Requirements by @shenkys as follows:

• Same height for the default render (meaning it can always be replaced with another render without needing to adjust the size for visual balance).
• Safe space only at the top edge (to allow for an animation of cable connection without being offset by the internal safe space).
• Height of 1200px; width is flexible. Each device can either have the same width or it can be standardized in some way, including safe spaces. However, scaling it in the app is not a problem.

[matejkriz]

@fang314 This is both user-facing (image for Modal T is not ideal now) and to make it easier for use to use.