Add support for configuration inheritance

**Describe the solution you'd like**
I wonder if we can provide a way to allow a configuration file to inherit from another one. Similar to TypeScript's `tsconfig.json`, this can be done by adding an `extends` property to specify the path to a base configuration file.

### Example
```JSONC
// bicepconfig.base.json
{
"analyzers": {
// ...
}
}
```

```JSONC
// bicepconfig.dev.json
{
"extends": "./bicepconfg.base.json"
"moduleAliases": {
"ts": {
"specs": {
"subscription": "...",
"resourceGroup": "test-rg"
}
}
}
}
```

```JSONC
// bicepconfig.prod.json
{
"extends": "./bicepconfg.base.json"
"moduleAliases": {
"ts": {
"specs": {
"subscription": "...",
"resourceGroup": "prod-rg"
}
}
}
}
```

The examples name bicepconfig.base.json, bicepconfig.dev.json, and bicepconfig.prod.json. Start by locating the configuration-loading entry point and related tests, then determine how an extends path and inherited settings should be resolved; done means derived configurations consistently load the base configuration and apply their overrides.

Written by the indexing model from the issue text.