Update sample doc to reflect newer odo url format

[scottkurz]

Old URL: <ep>-<comp>-<project/NS>-<host>

New URL: <ep>-<app>-<project/NS>-<host>

DISCUSSION

• multiple components within the same app have route creation conflict redhat-developer/odo#4957 (comment)
• odo list --app appName --project projectName confusing components with the same name in different applications redhat-developer/odo#4550

THINGS TO FIX

• odo.dev JPA article
• samples JPA README
• maybe more?