Improve rpcs support

[enomis-dev]

Linked to #316
This pull request aims to improve methods: copy_with(), footprint(), corners(), corner(), origin(), center(), resize() for rasters provided with rpcs.

[codecov-commenter]

Codecov Report

Merging #318 (12832b6) into master (2fe4388) will increase coverage by 0.03%.
The diff coverage is 96.22%.

@@            Coverage Diff             @@
##           master     #318      +/-   ##
==========================================
+ Coverage   90.86%   90.90%   +0.03%     
==========================================
  Files          38       38              
  Lines        6130     6176      +46     
==========================================
+ Hits         5570     5614      +44     
- Misses        560      562       +2     

Impacted Files	Coverage Δ
telluric/georaster.py	93.41% <93.33%> (-0.03%)	⬇️
tests/test_georaster.py	100.00% <100.00%> (ø)

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[enomis-dev]

Recently, I've seen that the current approach used to get corners and footprint could lead to error in mountains regions, further tests should be done.

[enomis-dev]

Recently, I've seen that the current approach used to get corners and footprint could lead to error in mountains regions, further tests should be done.

I added the possibility to pass the dem in the kwargs of the functions in case you want to get more precise results