support newer (v3) graphql-config file formats

[satyanash]

Currently, graphql-mode only looks for a single .graphqlconfig file. While this works okay, other editors/plugins such as IntelliJ etc will recommend upgrading to the v3 file format, as per these migration notes. Any project that has upgraded to the v3 file format will cease to work with graphql-mode and show the Could not find a .graphqlconfig file error message.

The (backward-incompatible) v3 file lookup allows for any of the following:

graphql.config.json
graphql.config.js
graphql.config.cjs
graphql.config.ts
graphql.config.toml
graphql.config.yaml
graphql.config.yml
.graphqlrc (YAML and JSON)
.graphqlrc.json
.graphqlrc.toml
.graphqlrc.yaml
.graphqlrc.yml
.graphqlrc.js
.graphqlrc.ts
graphql property in package.json

I don't think the graphql-mode package needs to support all of the above, but at least the json and yaml versions should be supported.