[app] Fix terminal for Kubernetes Pods

[ricoberger]

This commit fixes two smaller problems with the built-in terminal for
Kubernetes Pods:

• When a opened a terminal and then selected another container or shell
  to open a new terminal the commands where send twice to the terminal.
• When a user reached the end of a line the command overflows to the
  start of the line instead of a new line.

• I added a CHANGELOG entry for this change.
• I adjusted the corresponding documentation for this change.
• I adjusted the values.yaml file and the documentation for all values.

[codecov-commenter]

Codecov Report

Merging #391 (0401194) into main (17c699b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #391   +/-   ##
=======================================
  Coverage   45.20%   45.20%           
=======================================
  Files         134      134           
  Lines       10377    10377           
=======================================
  Hits         4691     4691           
  Misses       5608     5608           
  Partials       78       78           

---

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 17c699b...0401194. Read the comment docs.