Search should be case-insensitive

[joelverhagen]

/cc @shishirx34

In both Azure Search and old Lucene search there is clearly some search queries that work better if you give the search term "hints" by matching the original casing of, say, a package ID.

For example, sqlsugar vs. SqlSugar yield different results. This is non-intuitive. My theory is that the general expectation of users is that search is a case-insensitive thing and adding proper camel/pascal case to a search term has no effect. From the user's perspective this is just extra work to get the casing right when search should just figure it out for them

We should listen to customer feedback after Azure Search goes live and triage this pain point against others.

We can also improve the UX by adding simple help text saying "original casing helps search relevancy" or even a "did you mean" feature to rectify the casing.

[joelverhagen]

A more egregious example: https://www.nuget.org/packages?q=westwind.aspnetcore.markdown https://www.nuget.org/packages?q=Westwind.AspnetCore.Markdown

[bgrainger]

Another example:

• https://www.nuget.org/packages?q=MySQL returns 8,119 results, including "System.Data.SqlClient" in 6th place
• https://www.nuget.org/packages?q=mysql returns only 990 results, with a different ranking for the top 10

I would expect the count and order of results to be the same for both searches.