Code Scanning support for SARIF message string lookup in uploaded logs

The SARIF format supports the notion of indirect string lookups in its `message` object. Rather than directly providing a string in the `message.text` property, the indirect approach allows a specific set of other objects within the SARIF log to refer to the `message` object using its `id` property.

Currently, the CodeQL web service returns an error response when a log is uploaded which contains any `message` objects that don't provide a value in the `text` property:
`Error: Code Scanning could not process the submitted SARIF file: expected a result message`

The formal description of this feature and the decision tree for resolving the message string can be found here: [https://docs.oasis-open.org/sarif/sarif/v2.1.0/os/sarif-v2.1.0-os.html#_Toc34317468](https://docs.oasis-open.org/sarif/sarif/v2.1.0/os/sarif-v2.1.0-os.html#_Toc34317468)

No source files, tests, or entry points are named in the issue. Start by reproducing the upload error with a SARIF log containing an indirect message lookup, then follow the SARIF v2.1.0 message-string resolution decision tree. Done means uploaded logs using supported indirect message objects are processed without the expected-result-message error.

由索引模型根据 Issue 内容生成。