* add colorize_depth and matplotlib availability check
* add post_process_depth_estimation for zoedepth + tests
* add post_process_depth_estimation for DPT + tests
* add post_process_depth_estimation in DepthEstimationPipeline & special case for zoedepth
* run `make fixup`
* fix import related error on tests
* fix more import related errors on test
* forgot some `torch` calls in declerations
* remove `torch` call in zoedepth tests that caused error
* updated docs for depth estimation
* small fix for `colorize` input/output types
* remove `colorize_depth`, fix various names, remove matplotlib dependency
* fix formatting
* run fixup
* different images for test
* update examples in `forward` functions
* fixed broken links
* fix output types for docs
* possible format fix inside `<Tip>`
* Readability related updates
Co-authored-by: Pavel Iakubovskii <qubvel@gmail.com>
* Readability related update
* cleanup after merge
* refactor `post_process_depth_estimation` to return dict; simplify ZoeDepth's `post_process_depth_estimation`
* rewrite dict merging to support python 3.8
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Co-authored-by: Pavel Iakubovskii <qubvel@gmail.com>
