Some message strings in send_candidature_approuved_email.pt need to be transformed into variables

[SergioArbarviro]

Following commits b6f669ee2e3f1dad039968ed3f971d3166fec1ba to 1137292ff0ed0b43ef441a74e1e0402730b162ee, the following strings were inserted in the code of alirpunkto/locale/en/LC_MESSAGES/send_candidature_approuved_email.pt to alirpunkto/locale/ro/LC_MESSAGES/send_candidature_approuved_email.pt:

• ##PSEUDONYM
• ##LANGUAGE_1
• ##LANGUAGE_2
• ##LANGUAGE_3
• ##IS_COOPERATOR

These strings would need to be replaced by the relevant variables, which describe respectively:

• the user's Pseudonym;
• the user's first language of interaction;
• the user's second language of interaction;
• the user's third language of interaction;
• a boolean set at "true" when the user is registered as a Cooperator and to "false" otherwise.