Context names with whitespace don't work

[pranaysreeram]

Describe the bug
Kubectl works fine for contexts containing whitespace, but k9s does not. This is due to the string quoting issue.

To Reproduce
Steps to reproduce the behavior:

1. Go to kube config
2. Rename a context to include whitespace. For example, name "ctx1-aws" to "ctx1 (aws)"
3. In k9s, try to enter into that cluster
4. Get a "dial toast" error

Versions (please complete the following information):

• OS: OSX
• K9s: latest

Additional context
Add any other context about the problem here.

[pranaysreeram]

#3653

[pranaysreeram]

CC @derailed @mpas97 have pr for this, let me know if any other changes needed, thanks!