Oracle fix duplicate identifier for 3.2.x

[aimeos]

Q	A
Type	bug
BC Break	no
Fixed issues	N/A

Rebased #5000 to 3.2.x

Summary

The Oracle platform class creates duplicate identifier if the passed name is longer then 24 characters because the original code simply truncates everything beyond that limit. For example:

my_really_lengthy_table_name -> MY_REALLY_LENGTHY_TABLE_N_AI_PK
my_really_lengthy_table_name2 -> MY_REALLY_LENGTHY_TABLE_N_AI_PK

The database reports an already existing identifier and fails to proceed. This PR adds a three character random part if the identifier would be longer then allowed:

my_really_lengthy_table_name -> MY_REALLY_LENGTHY_TABL_EAD_SEQ
my_really_lengthy_table_name2 -> MY_REALLY_LENGTHY_TABL_085_SEQ

[morozov]

Next time, please do not file a new PR in order to rebase the changes. Edit the existing one instead.

sequences for tables with 27 to 30 characters change their name because the hash digits are added.

For an existing project, it means that if a table uses the sequence with the old name to implement autoincrement and starts using a new sequence, the next sequence value will be 1 which will likely break the application. The same was previously discussed in #4744 (comment).

[aimeos]

I've added the use function hash; line and used git commit --amend . && git push --force to update the PR but it's not visible here. Instead, Github only offers create a new PR. Any ideas how this can be solved?