Fix: status bar updates when editing inline $schema in YAML files

[shin19991207]

What does this PR do?

1. Before: status bar didn't update when you added inline $schema object to a YAML file
   Fix: status bar shows the schema immediately when you type it

2. Before: status bar only updated if you pasted the entire schema association line (modeline / inline $schema object) at once
   Fix: status bar updates as you type character-by-character

What issues does this PR fix or reference?

Fixes a bug from redhat-developer/yaml-language-server#970
Related to redhat-developer/yaml-language-server#1290

Is it tested? How?

• New automated test
• Tested manually with Fix: yaml/get/all/jsonSchemas returns schema association declared with inline $schema yaml-language-server#1290:
  • Create a schema file schema.json:

    {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "type": "object",
      "properties": {
        "$schema": {
          "type": "string"
        },
        "firstName": {
          "type": "string"
        }
      },
      "required": ["firstName"],
      "additionalProperties": false
    }

  • In YAML file, type the $schema object character-by-character:

    $schema: ./schema.json
    firstName: d

  • Verify that status bar updates after typing the schema path

[datho7561]

Looks good and fixes the issue. Thanks, Morgan!