Core search command fails with uppercase framework

[jmchiappa]

Bug Report

Current behavior

executing arduino-cli.exe core search STM32 fails even if framework is already installed.

The search always fails due to the search code which put in lowercase :

arduino-cli/cli/core/search.go

Line 58 in ebc28e1

arguments := strings.ToLower(strings.Join(args, " "))

Expected behavior

Searching (e.g. 'STM32' for STM32duino) framework should return the expected framework with all supported version

Environment

• CLI version : arduino-cli.exe Version: 0.10.0 Commit: ec5c3ed
• OS and platform:
  windows 10 x64 build 18363

--- EDIT ---
Even after rebuilding a new version without the strings.ToLower it doesn't seem to work as expected.
Not sure about the behavior of this command...

[umbynos]

This should be solved here #1904, please try it out