[internal]: port waitForEventInfo to the languages

[mxschmitt]

• Java fix: event info for waitForLoadState playwright-java#534
• Python fix: migrate to new waitForEventInfo handling playwright-python#824
• .NET fix: event info for waitForLoadState #1675

Reference: https://github.com/microsoft/playwright/pull/7413/files#diff-fae870e27eb3a7581eb788e4d30d71ae49f56e4d7b2e34b0a650870b8b7d1781
Drive-by: add waitForLoadState test if its not existing yet
Original issue: microsoft/playwright-python#820