Import ESP_UniClock (upstream 1189810)

Vendored from https://github.com/gpeter62/ESP_UniClock: the sketch
source, the web UI and the libraries the ESP8266 build needs, unpacked
from the bundled zips. Adds a PlatformIO project for the ESP-12. The
source is unchanged; local changes follow as separate commits.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

firmware/uniclock/lib/NTPClient/keywords.txt

@@ -0,0 +1,24 @@
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+NTPClient	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+begin	KEYWORD2
+end	KEYWORD2
+update	KEYWORD2
+forceUpdate	KEYWORD2
+isTimeSet	KEYWORD2
+getDay	KEYWORD2
+getHours	KEYWORD2
+getMinutes	KEYWORD2
+getSeconds	KEYWORD2
+getFormattedTime	KEYWORD2
+getEpochTime	KEYWORD2
+setTimeOffset	KEYWORD2
+setUpdateInterval	KEYWORD2
+setPoolServerName	KEYWORD2