[FotMob] Added support for retrieving "Expected goals on target (xGOT)" stats

[zack-fathi]

Changes Made

• Enhanced read_team_match_stats to recognize and extract the "xG on target (xGOT)" field from within the "Expected goals (xG)" section.
• Updated the test suite (test_read_team_match_stats) to include stat_type="Expected goals on target (xGOT)".

Closes #781 — This feature allows users to explicitly request xGOT data, which was previously included in the data but not directly accessible.

Note: CI failures are unrelated to this PR. The failing tests are in FiveThirtyEight and SoFIFA, which were not touched in this PR. Errors appear to be caused by external data sources returning unexpected or malformed data (e.g., HTML instead of JSON).