Change argument name file for template in gen_[tec,sta,ini]_xml functions

[sbuis]

In functions gen_usms_xml and gen_sols_xml, the argument file refers to the name of the file to crate, and there is an argument called template to provide the name of a template file.

In functions gen_tec_xml, gen_sta_xml, and gen_ini_xml, the name of the file to generate is set, not chosen by the user, but there is an argument called file to provide the name of a template file. Would be better if this argument is called template, to be homogeneous with th other functions (=> move file to deprecated argument).