Migrate Database and Hash functions to Util file

The SafeBrowsingUI file has hundreds of lines of code contained in
private functions. As outlined in the SafeBrowsingUI refactor document,
a new util file is to be created and filled with these private functions
as well as other structs that are shared across different classes used
in SafeBrowsingUI.

Since the amount of code that will be migrated to the new util file is
large, the migration will take place in steps. The second step, which
this CL covers, is to migrate the set of functions related to
the DatabaseInfo and HashInfo objects.

This is a multi-CL change:
  -  https://crrev.com/c/6621108
  => https://crrev.com/c/6638271
  -  https://crrev.com/c/6637992

Bug: 427719727
Change-Id: I3ff7b466ca488d9ebafc9f3c305287a91205ff15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6638271
Commit-Queue: Daniel White <danieltwhite@google.com>
Reviewed-by: thefrog <thefrog@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1484986}