Simplifies authentication

[wiltonsr]

• Remove the Authenticate and isDeprecatedUserParamError methods
• Using the Zabbix API version to determine the use of Login or LoginDeprecated
• This will prevent errors login in old Zabbix 3 as reported in Authentication broken for ancient Zabbix since support added for Zabbix 6.4 #1616

[CLAassistant]

All committers have signed the CLA.

[ivanahuckova]

@wiltonsr there has been some changes related to support of zabbix v7. The zabbix.api.Authenticate now accepts version, so you could just use your code in that method.

if zabbix.version >= 54 {
		auth, err = zabbix.api.Login(ctx, zabbixLogin, zabbixPassword)
	} else {
		auth, err = zabbix.api.LoginDeprecated(ctx, zabbixLogin, zabbixPassword)
	}