Plugins are ignored in call to setSchemaFromShowSchema

### Description

We have some custom plugins we are using and would like for them to appear as valid syntax in the editor. I don't see anything in the docs that shows how to do that, but the fact that Plugins are listed there makes it seem like they would be used when initializing the schema. When I look at the code I see that in normalizing the schema, only the Databases attribute is referenced, and Plugins are ignored. Is this something that is yet to be implemented? Or is there another way to configure this?

I have also asked this question: https://stackoverflow.com/questions/77246252/how-can-i-display-user-defined-plugins-for-kusto-in-the-monaco-editor

### Steps to Reproduce

1. Pass Schema.Result object with a defined Plugin to kusto worker via setSchemaFromShowSchema
2. Reference plugin in my app running Monaco Editor

```
{
"Plugins": [
{
"Name": "slice",
"InputParameters": [],
"Body": "",
"Folder": "",
"DocString": "I am a doc string",
"FunctionKind": "Unknown",
"OutputColumns": []
}
],
"Databases": {
"baz": {
"Name": "baz",
"Tables": {...
```

**Expected behavior:** The Plugin reference appears in intellisense autocomplete and does not appear as bad syntax

**Actual behavior:** The Plugin reference is treated as a syntax error

**Reproduces how often:** 100%

### System configuration

monaco-kusto version: 7.8.0
monaco-editor version: 0.40.0
Browser: Chrome
OS: Mac

Start at setSchemaFromShowSchema and trace schema normalization, focusing on how the Plugins attribute is handled compared with Databases. Reproduce the issue with the provided slice plugin in Monaco Editor; done means the plugin appears in IntelliSense autocomplete and is not reported as invalid syntax.

Written by the indexing model from the issue text.