[bitnami/postgresql] Postgresql global fullnameOverride fix

[KorenP1]

As for the last PR about global postgresql fullnameOverride. #33198 It is currently not functioning as expected.
The postgresql chart uses the "common.names.fullname" function and a local function called "postgresql.v1.primary.fullname" with some other naming functions.

When I changed the function "postgresql.v1.primary.fullname" in the last PR I wasnt paying attention to the other naming functions. and also the still using "common.names.fullname" function.

In order to solve this i have overriden the function "common.names.fullname" to use the "common.names.dependency.fullname" function (Couldn't override with the same function because it would end up in a recursion) which does the same but gets arguments for it. I have added an if else to override with the global.postgresql.fullnameOverride value. Also added .Chart.IsRoot validation because after overriding a function it is getting overriden in the whole context including subcharts. In this postgresql chart case its just in case this chart will somewhen use subchart which I dont think it will.

This whole PR is supposed to be a dialog with the mods because there are alot of ways to implement this global.postgresql.fullnameOverride feature, I chose the one i am offering here but i will describe also other ways that have come to my mind to implement it.

1. Abandon this feature and revert to a commit before the PR Mentioned above.

2. Overriding the function as i described earlier

3. Creating a new function that retrieves the general fullname and change every occurance of "common.names.fullname" to that new function

4. Implement some feature in the common chart

[KorenP1]

@javsalgar @juan131
Sorry for the misunderstanding in the last PR
Hopefully this one explains it better. Im availalbe for any questions.
Thanks. Koren.

[juan131]

We should try not to override any function from the common library. The option 3 you mentioned might be a better solution:

Creating a new function that retrieves the general fullname and change every occurrence of "common.names.fullname" to that new function