fix: [ANDROSDK-2194] Normalize server URL case for consistent database naming

[marcamsn]

Problem

• When users logged in with URLs that differed only in letter case (e.g., https://PLAY.DHIS2.ORG vs https://play.dhis2.org), the SDK would generate different database file names, potentially creating duplicate accounts for the same server.

Solution

• Add case normalization (lowercase) to processServerUrl() in DatabaseNameGenerator to ensure URLs with different letter casing generate the same database name
• Add integration tests to verify HTTP/HTTPS protocol switching and URL case variations are treated as the same account