feat: dependency graph with virtual packages

how is the dependency graph with "virtual packages" or dependency to capabilities?
see https://getcomposer.org/doc/04-schema.md#provide

these relations should result in a relation in the dependency graph.

example:
package `A` depends on `psr/log-implementation`
package `B` depends on `A` and depends on `cakephp/log` (which provides `psr/log-implementation`)

this means , that, effectively, a graph could look like:
```json5
[
{
ref: 'A',
dependsOn: ['psr/log-implementation'],
},
{
ref: 'B',
dependsOn: ['A', 'cakephp/log'],
},
{
ref: 'psr/log-implementation',
dependsOn: ['cakephp/log'],
},
{
ref: 'cakephp/log'
},
]
```