Remove every references to file path in the JSON-RPC wallet API

[ValentinTrinque]

Some JSON-RPC params and results have field with filePath in it. It should be removed.

• Create wallet
• import wallet
• import network
• isolate key

If something need to display the path, it should be acquired outside of the API itself, directly from the Store structs

Tasks

• Remove filePath from methods defined above
• Edit OpenRPC documentation
• Remove deprecated use of Version (when replaced by KeyDerivatioVersion)
• Keep a single field to import a network (URL over file path), and prefix by file:// in the CLI when it's a file
• Bonus Support path alias (such as ~) in the file path input.

[emilbayes]

Today we discussed whether admin.impot_wallet should only take a url parameter, and then allow for the URL to reference eg. file:// if the "backend" supports it. This is a consideration for eg. web wallet which may support loading configs from remote URLs but perhaps not read the local file system.
In the same method a name parameter exists, but the network config also contains a name. The API needs some clarity about how to reconcile the two or perhaps drop one of them.