Response Correlation Viewer: Disable sliding in observation selector

[valentin-krasontovitsch]

Describe the bug
The observation selector allows for displaying observations from several responses. When responses with different axis (units) are displayed, the sliding functionality of the plot for the upper axis does not interact well with the selection rectangle.

To Reproduce
Steps to reproduce the behavior:

1. Open up webviz-ert with data that containts at least two responses with observations with different axes (e.g. in ert, test-data/local/snake_oil)
2. Navigate to the response correlation viewer
3. Choose one ensemble and two responses with axes with different units (e.g. FOPR and SNAKE_OIL_WPR_DIFF@199
4. Draw a rectangle to select a couple of observations (at least one)
5. Draw the upper axis of the observation selector plot left or right
6. Observe that the upper observation points move, while the selection rectangle, the lower points, and the observation selection remain constant
7. Likewise, when dragging the lower axis, the rectangle and the lower points move, but the upper points remain stationary, and the selection does not change.

Expected behavior
For example both axes and all points and the rectangle always move, and the selection remains constant, or whenever only parts move, the selection is updated to reflect the new visual situation.

We suggest disabling the sliding of the axes in the observation selector plot completely, cf. (bits of a discussion on the observation selector PR)[https://github.com//pull/384#issuecomment-1230216478]