add: sqlite db and schema

server/sql_db/schema.sql

+CREATE TABLE Measurement (
+    MeasurementID INT PRIMARY KEY,
+    SensorID INT,
+    TimeMeasured DATETIME,
+    Latitude FLOAT,
+    Longitude FLOAT,
+    MeasuredThickness FLOAT,
+    Accuracy FLOAT,
+    FOREIGN KEY (SensorID) REFERENCES Sensor(SensorID)
+);
+
+CREATE TABLE Sensor (
+    SensorID INTEGER PRIMARY KEY,
+    SensorType TEXT CHECK(SensorType IN ('LiDar', 'Magnetic', 'Other')),
+    Active BOOLEAN
+);
+
+INSERT INTO Sensor (SensorID, SensorType, Active) VALUES
+(1, 'LiDar', 1),
+(2, 'Magnetic', 1),
+(3, 'Other', 0);
+
+INSERT INTO Measurement (MeasurementID, SensorID, TimeMeasured, Latitude, Longitude, MeasuredThickness, Accuracy) VALUES
+(1, 2, '2024-01-01 10:00:00', 60.7066, 10.9771, 10.0, 1.0),
+(2, 2, '2024-02-04 11:00:00', 60.6366, 10.8171, 7.8, 1.5),
+(3, 1, '2024-02-13 12:00:00', 60.7366, 10.8471, 7.2, 2.5);