feat: process embedded languages in text blocks with language identifier comments

[jtkiesel]

What changed with this PR:

This is working, but as soon as an embed function is provided on our printer, even if its implementation is simply return null;, our printer slows to a crawl. More investigation will need to be done to determine why this is the case, and whether it can easily be resolved. Until then, this feature cannot be merged, or it will cause severe slowness for all uses of this plugin (whether they contain embedded languages or not).

Example

Input

void example() {
  // language=json
  String config = """
        {   "name":"example",
    "enabled"   :true,
          "timeout":30}
  """;

  /* language = JSON */
  String query = """
       {
     "sql":"SELECT * FROM users \
  WHERE active=1 \
  AND deleted=0",
     "limit":10}
  """;
}

Output

void example() {
  // language=json
  String config = """
    { "name": "example", "enabled": true, "timeout": 30 }
    """;

  /* language = JSON */
  String query = """
    {
      "sql": "SELECT * FROM users WHERE active=1 AND deleted=0",
      "limit": 10
    }
    """;
}

Relative issues or prs:

Closes #794