• right now the ssh config is triggered only when at the login and only when new workspaces are
  created. In the last case, the ssh config updates only the new sections.
• but the user can go into settings page and enable or disable the wildcard ssh config. With this patch
  after the user hits Save, the ssh re-configuration is triggered, without the need to restart Toolbox.

Also a major fix - read only settings acted as snapshots in the sense that they did not reflect any subsequent update to the underlying store because updates create a new readonly instance

• with this patch we simplified the code even more by exposing a readonly interface with all of the
  implementation in the CoderSettingsStore. PluginSettingsStore and Environments are the only persist-able
  stores.
• because read only instances share the same settings store instances any update on the writable will reflect
  on the readable instances as well.