Documentation Update: list of widgets

Here's a list of outdated documentation files to keep track when updating. List based only on the images. Cannot think how to easily inspect text-based changes. Some have only minor changes. Many have only Report (or similar) moved to status bar, they aren't listed here. That said, it might make sense to update them at some point, just to have a full update every ... 10 years? :)

# Data
- [ ] File #6966
- [ ] Datasets #6967
- [ ] Data Table #6968
- [ ] SQL Table
- [ ] Paint Data #6977
- [ ] Data Info #6978
- [ ] Edit Domain
- [ ] Color (Save, Load, Reset buttons added) #6981

# Transform
(resolved in https://github.com/biolab/orange3-doc-visual-programming/pull/7)
- [x] Data Sampler
- [x] Select Columns
- [x] Select Rows (minimal)
- [x] Transpose
- [x] Merge Data (minimal)
- [x] Select By Data Index
- [x] Aggregate Columns
- [x] Group by (some aggregations added and order changed)
- [x] Apply Domain
- [x] Impute
- [x] Continuize (wording different)
- [x] Randomize (minor)
- [x] Purge Domain (minor)
- [x] Formula (no change but VERY poor quality image)
- [x] Create Class
- [x] Python Script

# Visualize
(resolved in https://github.com/biolab/orange3-doc-visual-programming/pull/2)
- [x] Tree Viewer
- [x] Distribution
- [x] Scatter Plot
- [x] Line Plot (very minor)
- [x] Sieve Diagram (very minor)
- [x] Mosaic Display
- [x] FreeViz
- [x] RadViz
- [x] Heat Map (low-high to range)
- [x] Pythagorean Tree (very minor)
- [x] Nomogram
- [x] Scoring Sheet Viewer (should be redone after #6924 to have the same results each time)

# Model
- [x] Logistic Regression
- [x] AdaBoost
- [x] Neural Network
- [x] Stochastic Gradient Descent
- [x] Save Model

# Evaluate
- [x] Test and Score
- [x] Predictions
- [x] Confusion Matrix
- [ ] Performance Curve (minor)
- [x] Parameter Fitter (missing Example)

# Unsupervised
- [x] Distance File
- [x] Correlations
- [x] Distance Map (low-high to range)
- [x] Hierarchical Clustering
- [x] Manifold Learning (minor)
- [x] PCA (minor)
- [x] Neighbors (minor)
- [x] Distances
- [x] MDS
- [x] Save Distance Matrix

Start with the remaining unchecked widget entries under Data and Evaluate, using the referenced issues such as #6966, #6967, #6968, #6977, #6978, and #6981 where available. Compare each widget's current documentation images and text with the present interface. Done means the remaining outdated entries are updated and checked off, including Performance Curve.

Written by the indexing model from the issue text.