Add possibility to expand already defined custom avro types

[szczygiel-m]

Adjust schema visualization presented on Hermes console for records which are used repeatedly in one schema. Now it displays the record type only (without nested fields inside record).

Record definition:

{
"type": "record",
"name": "MarketplaceId",
"namespace": "pl.allegro.{...}.marketplace",
"fields": [
{
"name": "id",
"type": "string",
}
]
}

Record usage:

{
"name": "marketplace",
"type": "pl.allegro.{...}.marketplace.MarketplaceId",
}

Example visualization:

[MiloszKorman]

Hey! I'd like to give this issue a go for hacktoberfest 😄

[szczygiel-m]

Hey, cool to hear that 😄 assigned. If you have any questions/problems, let us know.