Description
Is your feature request related to a problem? Please describe.
If in the etc/config.xml file there was support for an autocomplete of available scopes, sections, groups, and fields, which would make it easier to work with this file.
Currently when editing the etc/config.xml file developer need to constantly switch between etc/adminhtml/system.xml to copy the correct group or field name.
And this still does not guarantee that the error will not be made, since developer can insert the copied value in the wrong section or in the wrong group.
There may also be problems when inserting values in a scope other than default, the field may only be available at the website level, and the developer may insert it at the store level. there are even configs that are not available in scope by default.
Describe the solution you'd like
For the etc/config.xml file a full autocomplete must be added.
At the first level, there should be support for all possible scopes (default/websites/stores/etc) here is an example from the Magento_Backend module.
Then there should be sections from the current module from the file etc/adminhtml/system.xml, the sorting should be according to the sortOrder field of these sections, after these sections the sections from the modules that are specified in the sequence in the module.xml file can be listed, then the remaining sections from other modules can be listed.
Within the sections, the groups that are located within this section should be available, and the sorting should also be according to the sortOrder values.
Within the groups, the corresponding fields are displayed, sorted by the value of sortOrder.
It is very important to add proper support for attributes showInDefault="1" showInWebsite="1" showInStore="1".
If some attribute indicates that this section/group/field is not available for this scope, then the line in the proposed options should be crossed out (as it works for @deprecated in php code), but it should be available for selection, since sometimes the field may have incorrect attributes due to bugs or due to accident.
It is also important to add a new type of inspection that will check the file etc/config.xml for the presence of undescribed/incorrect/invalid combinations of scope/section/group/field. Also, when editing this file, contributors can highlight/cross out all such places so that it immediately catches developer's eye when developer open this file.
Additional context
For scopes websites/stores, developer need to specify the store code for which the specified values will be applied. One of the possible values is the backend store code admin. Most likely, it is not possible to support other store codes from the database, without implementing support for reading values from the database. Maybe contributors have some options for implementing store codes.
https://devdocs.magento.com/guides/v2.4/config-guide/config/config-files.html
https://devdocs.magento.com/guides/v2.4/config-guide/prod/config-reference-systemxml.html
It would also be very good to add similar support to the common file app/etc/config.php since developer can also specify default values there. And when working on the Magento Cloud Edition, a lot of things are configured through this file.
https://devdocs.magento.com/guides/v2.4/config-guide/prod/config-reference-configphp.html
https://devdocs.magento.com/cloud/live/sens-data-over.html#update-configurations
https://devdocs.magento.com/cloud/live/sens-data-initial.html