SSH key passphrase support in ssh2 transport

[ghost]

Description

Added support for SSH key passphrase in SSH2 transport.
No issue was opened, but got spotted while using the library.

Type of change

Please delete options that are not relevant.

• [ x ] New feature (non-breaking change which adds functionality)
• [ x ] This change requires a documentation update

How Has This Been Tested?

Used a similar template to the one in example/basic_usage for GenericDriver, where
specified the ssh_private_key_passphrase parameter in MY_DEVICE config.

The listening OpenSSH server was setup to accept just a SSH key protected by a password.

[codecov]

Codecov Report

Merging #192 (fe7ada0) into develop (7af5387) will decrease coverage by 0.07%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #192      +/-   ##
===========================================
- Coverage    91.04%   90.96%   -0.08%     
===========================================
  Files           58       58              
  Lines         3304     3275      -29     
===========================================
- Hits          3008     2979      -29     
  Misses         296      296              

Impacted Files	Coverage Δ
scrapli/transport/plugins/ssh2/transport.py	32.57% <100.00%> (+0.51%)	⬆️
scrapli/logging.py	83.49% <0.00%> (-0.62%)	⬇️
scrapli/ssh_config.py	98.87% <0.00%> (-0.07%)	⬇️
scrapli/factory.py	95.83% <0.00%> (-0.03%)	⬇️
scrapli/channel/async_channel.py	95.65% <0.00%> (-0.02%)	⬇️
scrapli/channel/sync_channel.py	97.27% <0.00%> (-0.02%)	⬇️
scrapli/helper.py	100.00% <0.00%> (ø)
scrapli/response.py	100.00% <0.00%> (ø)
scrapli/driver/generic/base_driver.py	100.00% <0.00%> (ø)
scrapli/driver/generic/sync_driver.py	98.14% <0.00%> (ø)
... and 14 more

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[carlmontanari]

Hey @shnurty thanks for putting this together! Looks cool -- I'll try to test it out this weekend so we can get it merged in.

Could you update to point to the develop branch please? Last thing for now: we can ignore that doc-test CI failing right now... haven't looked at that yet but it just fails sometimes :)

Carl

[ghost]

Hi @carlmontanari, thanks :)
Always a pleasure to help with such interesting and useful projects.

I've target the develop branch directly from GH.
No hurry for the review: let me know if you want me to add/modify something in case.

PS: the new "commit" is for adding a space between the comma and the beginning of the next var in HTML doc.
I noticed it and it was hurting ;)

[carlmontanari]

Took this for a test drive and looks good to go, thanks for the work on this!

Carl