Support expression-bodied (lambda) read-only properties in C#

[aalramadan]

Read-only properties are defined with expression-bodied (lambda) syntax such as:

public string Data => "Hello from the default";

srcML:

<expr_stmt><expr><specifier>public</specifier> <name>string</name> <lambda><parameter_list type="pseudo"><parameter><decl><name>Data</name></decl></parameter></parameter_list> =&gt;<block type="pseudo"><block_content> <expr><literal type="string">"Hello from the default"</literal></expr></block_content></block></lambda></expr>;</expr_stmt></unit>

And are used to declare implicit read-only fields. Stereocode does not collect these as they are tagged with <expr_stmt>. Stereocode currently only collects properties with the <property> tag (e.g., auto-properties or regular properties).