70 - Can't enter @ in password input box

Fixes #70

Description

Fixed Issue 70: Unable to type characters with CTRL+ALT (e.g. italian layout CTRL+ALT+ò => @) due to a crossterm issue. Fixed with tui-realm-stdlib 0.6.3.
Improved Context terminal functions (empty impl in Windows)
Removed optional compile for enter alternate screen (just leave them empty on Windows).

Please select relevant options.

[x] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
[ ] This change requires a documentation update

[x] My code follows the contribution guidelines of this project
[x] I have performed a self-review of my own code
[x] I have commented my code, particularly in hard-to-understand areas
[x] My changes generate no new warnings
[x] I formatted the code with cargo fmt
[x] I checked my code using cargo clippy and reports no warnings
[x] I have added tests that prove my fix is effective or that my feature works
[x] I have introduced no new C-bindings
[x] The changes I've made are Windows, MacOS, UNIX, Linux compatible (or I've handled them using cfg target_os)
[x] I increased or maintained the code coverage for the project, compared to the previous commit

wait for a project maintainer to fulfill this section...

[x] regression test: open text file windows won't crash termscp
[x] As windows user, I can now type a character made up with CTRL+ALT(+SHIFT) in input fields.