fix(select): correctly handle reset value when multiple is on

[chirichok98]

Please read and mark the following check list before creating a pull request:

• I read and followed the CONTRIBUTING.md guide.
• I read and followed the New Feature Checklist guide.

Short description of what this resolves:

Fixes #1950. Fixes #2484.

Before fix:
form.reset() sets null for each control in form and null is not an array. Error was produced.

After fix:
When select is multiple we have additional check on null and undefined (in this case value will be empty array)

[yggg]

Please, could you also check if autocomplete has the same problem? And if so, fix it as well.

[chirichok98]

Comments were fixed. Added return for empty value on selectValue.

[chirichok98]

Please, could you also check if autocomplete has the same problem? And if so, fix it as well.

We have no possibility there to choose multiple items. Nothing to fix.

[chirichok98]

Reviewed and applied change request