Fix and improve support for TDEngine `insert` syntax.

1. Support inserting into multi-table in the template

   For example:

   `insert into table_1 values (${ts}, '${id}', '${topic}')
   table_2 values (${ts}, '${id}', '${topic}')`

2. Support mixing prefixes/suffixes and placeholders in the template

   For example:

   `insert into table_${topic} values (${ts}, '${id}', '${topic}')`

Note: This is a breaking change. Previously the values of string type were quoted automatically, but now they must be quoted explicitly.

For example:

`insert into table values (${ts}, '${a_string}')`