v1.4.0 to enable scan of WiFi networks

### Major Releases v1.4.0

1. Enable scan of WiFi networks for selection in Configuration Portal. Check [PR for v1.3.0 - Enable scan of WiFi networks #10](khoih-prog/WiFiManager_NINA_Lite#10). Now you can select optional **SCAN_WIFI_NETWORKS**, **MANUAL_SSID_INPUT_ALLOWED** to be able to manually input SSID, not only from a scanned SSID lists and **MAX_SSID_IN_LIST** (from 2-15)
2. Fix invalid "blank" Config Data treated as Valid.
3. Permit optionally inputting one set of WiFi SSID/PWD by using `REQUIRE_ONE_SET_SSID_PW == true`
4. Enforce WiFi PWD minimum length of 8 chars
5. Minor enhancement to not display garbage when data is invalid

Author: khoih-prog