Simplify Whiten syntax

[garrettwrong]

Allows passing NoiseEstimator instance directly to ImageSource.whiten().

Still allows passing a Filter directly.

Raises error if neither style of input is satisfied.

Closes #878

[codecov]

Codecov Report

Merging #883 (17094d6) into develop (d9a761c) will increase coverage by 0.23%.
The diff coverage is 87.75%.

@@             Coverage Diff             @@
##           develop     #883      +/-   ##
===========================================
+ Coverage    88.62%   88.86%   +0.23%     
===========================================
  Files          117      117              
  Lines         9586     9949     +363     
===========================================
+ Hits          8496     8841     +345     
- Misses        1090     1108      +18     

Impacted Files	Coverage Δ
src/aspire/commands/denoise.py	0.00% <0.00%> (ø)
src/aspire/commands/preprocess.py	0.00% <0.00%> (ø)
src/aspire/source/image.py	92.30% <90.90%> (+1.03%)	⬆️
src/aspire/commands/extract_particles.py	86.79% <100.00%> (ø)
src/aspire/image/image.py	93.07% <100.00%> (+0.66%)	⬆️
src/aspire/source/__init__.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more