fix: add more checks for existing approot

[stasadev]

The Issue

app.CheckExistingAppInApproot() does not work properly if you run ddev config several times and change the project name:

$ ddev config --project-name=d10
Creating a new DDEV project config in the current directory (/home/stas/code/ddev/d10) 
Once completed, your configuration will be written to /home/stas/code/ddev/d10/.ddev/config.yaml
 
Configuring a 'php' project with docroot '' at /home/stas/code/ddev/d10 
Configuration complete. You may now run 'ddev start'. 

$ ddev config --project-name=d10-rename
You are reconfiguring the project at /home/stas/code/ddev/d10.
The existing configuration will be updated and replaced.
Configuring a 'php' project with docroot '' at /home/stas/code/ddev/d10
Configuration complete. You may now run 'ddev start'.

$ ddev config --project-name=d10-rename-2
this project root /home/stas/code/ddev/d10 already contains a project named d10. You may want to remove the existing project with "ddev stop --unlist d10"

The ~/.ddev/project_list.yaml file:

d10:
    approot: /home/stas/code/ddev/d10
d10-rename:
    approot: /home/stas/code/ddev/d10

How This PR Solves The Issue

Adds app.CheckExistingAppInApproot() to more places.

Manual Testing Instructions

$ ddev config --project-name=d10

$ ddev config --project-name=d10-rename
You are reconfiguring the project at /home/stas/code/ddev/d10.
The existing configuration will be updated and replaced.
this project root /home/stas/code/ddev/d10 already contains a project named d10. You may want to remove the existing project with "ddev stop --unlist d10"

$ echo d10-rename | ddev config
You are reconfiguring the project at /home/stas/code/ddev/d10.
The existing configuration will be updated and replaced.
Project name (d10): this project root /home/stas/code/ddev/d10 already contains a project named d10. You may want to remove the existing project with "ddev stop --unlist d10"

Automated Testing Overview

Related Issue Link(s)

Release/Deployment Notes

[github-actions]

Download the artifacts for this pull request:

• all-ddev-executables.zip
• ddev-linux-amd64.zip
• ddev-linux-arm64.zip
• ddev-macos-amd64.zip
• ddev-macos-arm64.zip
• ddev-windows-amd64-installer.zip

See Testing a PR.

[bmartinez287]

A safety check based around a consistent outcome seems like great idea.

[rfay]

Looks great to me, tests fine, thanks!