chore: Checking ShellCheck errors and applying relevant fixes (#1305)

* Checking shellCheck fix - for db_copyfile

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Adding double quotes to all arrays in db_copy script. Reason: Error SC2068

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Fixing SC2145 errors in prepare-restricted-environment script

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Fixing SC2206 errors -Quote to prevent word splitting/globbing - in prepare-restricted-environment script

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Fixing comments to ignore certain warnings. Adjusting code to fix warning - SC2178 and SC2128.

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Updating db_copy.sh file with necessary changes. Quoting all variables.

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Running script and making changes to ensure it runs to completion

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Changing lines to ensure script runs correctly without errors

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Updating db_copy based on PR feedback

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Slight changes based on PR feedback

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Making changes based on suggestions

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Fixing missed errors and small mistake

Signed-off-by: Leanne Ahern <lahern@redhat.com>

* Update .rhdh/scripts/prepare-restricted-environment.sh

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Signed-off-by: Leanne Ahern <lahern@redhat.com>
Co-authored-by: Armel Soro <armel@rm3l.org>

Author: OpinionatedHeron