fix: base_url not generated from spec [#6663]

[filfreire]

Closes #6663

Because there's already a baseEnvironment in the workspace, we ignored the one from openapi-3 importer.

This fix will make it so the .data of the workspace's base environment will get replaced with what comes from the importer - so that the requests will work as {{_.base_url}} will now get added into the base environment.

Note: Another issue, though it can be handled in a separate PR - when importing a spec - it follows through the scanResources and points out envs and requests correctly - but this is only used for the preview part of import - once we import, we create an almost empty design doc, with only the spec filled out