Move as much as possible related to tools out of qt-specific directories

[astrofrog]

This is so that we can use them in glue-viz/glue-jupyter#92 without having to import Qt

[codecov]

Codecov Report

Merging #1984 into master will decrease coverage by 0.06%.
The diff coverage is 85.94%.

@@            Coverage Diff             @@
##           master    #1984      +/-   ##
==========================================
- Coverage   87.76%   87.69%   -0.07%     
==========================================
  Files         243      247       +4     
  Lines       21662    21669       +7     
==========================================
- Hits        19012    19003       -9     
- Misses       2650     2666      +16

Impacted Files	Coverage Δ
glue/viewers/matplotlib/mouse_mode.py	97.72% <ø> (ø)
glue/viewers/profile/qt/data_viewer.py	100% <ø> (ø)	⬆️
glue/viewers/matplotlib/__init__.py	100% <100%> (ø)
glue/viewers/common/qt/toolbar.py	97.16% <100%> (ø)	⬆️
glue/core/roi.py	93.77% <100%> (ø)	⬆️
glue/viewers/table/qt/data_viewer.py	96.85% <100%> (ø)	⬆️
glue/viewers/matplotlib/qt/toolbar.py	97.14% <100%> (ø)	⬆️
glue/viewers/image/qt/contrast_mouse_mode.py	60% <100%> (ø)	⬆️
glue/viewers/matplotlib/toolbar_mode.py	96.21% <100%> (ø)
glue/viewers/matplotlib/qt/__init__.py	100% <100%> (ø)
... and 16 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1c99842...89ac334. Read the comment docs.

[astrofrog]

The remaining Travis failures are unrelated, I will investigate/fix in a separate PR.