Unhandled error in liquidity pool search field

**Describe the bug**

I can't perform a search for the UIA to be converted to a liquidity pool token with my account 'nft.artist'.

I therefore can't create a liquidity pool with this account.

**To Reproduce**
Steps to reproduce the behavior:

Explore to the account `nft.artist`, then go to advanced -> pools -> Create.

Within the first field, search for NFTEA.

Nothing happens, however the console reports the following errors:

```
getAssetsByIssuer id = nft.artist_10
{
"code": 7,
"message": "Execution error: Bad Cast: Invalid cast from type 'null_type' to Object",
"data": {
"code": 7,
"name": "bad_cast_exception",
"message": "Bad Cast",
"stack": [
{
"context": {
"level": "error",
"file": "variant.cpp",
"line": 579,
"method": "get_string",
"hostname": "",
"thread_name": "th_a",
"timestamp": "2023-01-13T00:48:24"
},
"format": "Invalid cast from type '${type}' to Object",
"data": {
"type": "null_type"
}
},
{
"context": {
"level": "warn",
"file": "object_id.hpp",
"line": 265,
"method": "from_variant",
"hostname": "",
"thread_name": "th_a",
"timestamp": "2023-01-13T00:48:24"
},
"format": "",
"data": {
"var": null
}
}
]
}
}
```

If I use another account which doesn't include a dot in the middle, the first field's search box works as expected.

**Expected behavior**
I'm able to create a liquidity pool token with this account, getting past the first field.

**Desktop (please complete the following information):**
Desktop, windows 11.
Occurs on web too.

Reproduce the failure from the account view at Advanced → Pools → Create by searching for NFTEA in the first field, and inspect the console output from getAssetsByIssuer. Compare the behavior with an account name that has no dot. Done means the search completes without the reported null_type error and allows the liquidity-pool creation flow to pass the first field.

Written by the indexing model from the issue text.