Add utils to convert between Protobuf Timestamp/Duration to java.time equivalent

* Scaffold :exts:protobuf:temporal module
* Add module to settings script

Author: EdricChan03

exts/protobuf/temporal/.gitignore

@@ -0,0 +1 @@
+/build

exts/protobuf/temporal/build.gradle.kts

@@ -0,0 +1,8 @@
+plugins {
+    com.edricchan.studybuddy.library.kotlin
+    com.edricchan.studybuddy.library.testing.`kotest-junit5`
+}
+
+dependencies {
+    api(libs.protobuf.kotlin.lite)
+}

exts/protobuf/temporal/src/main/kotlin/com/edricchan/studybuddy/exts/protobuf/temporal/ProtoDurationExts.kt

@@ -0,0 +1,16 @@
+package com.edricchan.studybuddy.exts.protobuf.temporal
+
+import com.google.protobuf.duration
+import java.time.Duration
+// We use DurationP instead of DurationProto as there's also a class with the same name
+// in the package
+import com.google.protobuf.Duration as DurationP
+
+fun DurationP.toJavaDuration(): Duration = Duration.ofSeconds(
+    seconds, nanos.toLong()
+)
+
+fun Duration.toProtoDuration(): DurationP = duration {
+    seconds = this@toProtoDuration.seconds
+    nanos = this@toProtoDuration.nano
+}

exts/protobuf/temporal/src/main/kotlin/com/edricchan/studybuddy/exts/protobuf/temporal/ProtoTimestampExts.kt

@@ -0,0 +1,11 @@
+package com.edricchan.studybuddy.exts.protobuf.temporal
+
+import com.google.protobuf.Timestamp
+import com.google.protobuf.timestamp
+import java.time.Instant
+
+fun Timestamp.toInstant(): Instant = Instant.ofEpochSecond(seconds, nanos.toLong())
+fun Instant.toTimestamp(): Timestamp = timestamp {
+    seconds = epochSecond
+    nanos = nano
+}

settings.gradle.kts

@@ -151,6 +151,7 @@ include(
     ":exts:firebase:temporal",
     ":exts:material",
     ":exts:material:date-picker",
+    ":exts:protobuf:temporal",
     ":features:help",
     ":features:auth",
     ":features:settings",