Task: rename our templates db `Mock_DB_V2`

[rahulbarwal]

• Name of our DB must accurately represent its intend and should not be confusing to our users.
• We also have to ensure after update existing apps don't break.
• One idea🤔 is to set up an alias and use that alias going forward.

[rahulbarwal]

Can be done alongside #33084

[jacquesikot]

All templates and building blocks datasource names have been changes from Mock_DB_V2 to Sample Database