More localization friendly source strings and context commenting

[AmelBawa-msft]

What was done?

• Added support for string localization with placeholders. For example:

<data name="CommandArgumentDescription" xml:space="preserve">
    <value>Filter results by command</value>
</data>
<data name="InvalidArgumentValueError" xml:space="preserve">
    <value>The value provided for the `{0}` argument is invalid; valid values are: {1}</value>
    <comment>Error message displayed when the user provides an invalid command line argument value. {0} is a placeholder replaced by the argument name. {1} is a placeholder replaced by a list of valid options.</comment>
</data>

info << String::CommandArgumentDescription;                           // => Filter results by command
info << String::InvalidArgumentValueError("First"_liv, "Second"_liv); // => The value provided for the `First` argument is invalid; valid values are: Second

• Applied the localization placeholder change to most use cases in the code. Some remaining use cases (e.g. ShowFlow.cpp) will be handled separately as it contains localized strings with a special rendering style (e.g. text printed in bold, different color, etc...).
• Updated existing unit tests
• Documented strings with placeholders in the winget.resw file.

Test

• Tested locally a randomly selected set of localized strings with placeholders.
• Added unit tests for newly added functions

Microsoft Reviewers: Open in CodeFlow

[florelis]

Nit: I don't think the comment "Resolve the string id" is saying much for the Resolve() function... I'd prefer the comment to explain what "resolve" means or what it resolves to. Something like "resolves the string ID to the localized string it represents, keeping replacement tokens"

[yao-msft]