fix: SSH Tunnel configuration settings

[geido]

SUMMARY

This PR fixes several issues with the SSH Tunnel option in the Database Modal which are related to edit the SSH Tunnel config, enable/disable the option, and misc fixes/enhancements. In particular:

• Removes a duplicate SSHTunnelSwitch component from dynamic forms and merges the logics of both dynamic and SQLAlchemy forms into one overridable component
• Fixes an issue that made removing the SSH tunnel config impossible when editing a database connection
• Delegates the deletion of a ssh tunnel to the UpdateDatabaseCommand
• Fixes an issue with the SSH tunnel config still being included in the request even when toggled off
• Fixes an issue for which the switch was showing also with SSH_TUNNELING OFF. Saving would cause a "SSH Tunneling is not enabled" error
• Surfaces to the user a missing port error in the SQLAlchemy uri when enabling SSH Tunnel (the port is required for the tunnel to work)
• Clean the SSH Tunnel config from unnecessary credentials when switching from password to private key
• Improves the UX so that toggling ON and OFF the SSH Tunnel config won't clear the form until saved
• Misc fixes

BEFORE

DEV.Superset.mp4

AFTER

DEV.Superset.1.mp4

TESTING INSTRUCTIONS

1. Create a new database connection using a SQLAlchemy uri and dynamic forms, make sure SSH Tunnel can be toggled ON and OFF and that configs can be saved successfully
2. Edit a database connection that has a SSH Tunnel config, make sure the SSH Tunnel can be toggled ON and OFF and that it keeps the config available to the user until toggled OFF and saved
3. Edit a database connection that has a SSH Tunnel config, make sure any change to the SSH tunnel can be saved successfully
4. Re-open the database config and make sure the SSH Tunnel has been deleted successfully
5. Create or edit a database connection using a SQLAlchemy uri without specifying the port, make sure an error is surfaced to the UI informing that specifying a port is necessary

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[codecov]

Codecov Report

Attention: Patch coverage is 82.11382% with 22 lines in your changes are missing coverage. Please review.

Project coverage is 69.73%. Comparing base (fde93dc) to head (ec8c5f4).

Files	Patch %	Lines
...end/src/features/databases/DatabaseModal/index.tsx	61.90%	6 Missing and 2 partials ⚠️
superset/commands/database/update.py	74.07%	7 Missing ⚠️
superset/commands/database/test_connection.py	80.00%	4 Missing ⚠️
superset/commands/database/ssh_tunnel/update.py	85.71%	2 Missing ⚠️
...ses/DatabaseModal/DatabaseConnectionForm/index.tsx	88.88%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #27186      +/-   ##
==========================================
+ Coverage   67.34%   69.73%   +2.38%     
==========================================
  Files        1909     1909              
  Lines       74623    74670      +47     
  Branches     8324     8324              
==========================================
+ Hits        50255    52069    +1814     
+ Misses      22314    20550    -1764     
+ Partials     2054     2051       -3     

Flag	Coverage Δ
hive	53.73% <20.77%> (?)
javascript	57.21% <80.43%> (+0.01%)	⬆️
mysql	78.02% <81.81%> (+0.02%)	⬆️
postgres	78.12% <81.81%> (+0.02%)	⬆️
presto	53.68% <20.77%> (?)
python	83.15% <83.11%> (+4.92%)	⬆️
sqlite	77.57% <41.55%> (-0.05%)	⬇️
unit	56.55% <51.94%> (?)

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[kgabryje]

Added a few nonblocking comments but looks great!

[dpgaspar]

a couple of non blocking comments

[github-actions]

@geido Ephemeral environment spinning up at http://35.89.241.113:8080. Credentials are admin/admin. Please allow several minutes for bootstrapping and startup.

[github-actions]

Ephemeral environment shutdown and build artifacts deleted.