Added Election Term Metric

[meetshah777]

This Metric will Publish the Only Election term number

Tests: Docker Container Testing

1. Schema of Election term

sqlite> .schema Election_Term
CREATE TABLE Election_Term(sum double null, avg double null, min double null, max double null);

2. Entry in Election term table

sqlite> select * from Election_Term;
18.0|18.0|18.0|18.0

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