fix solution update issues

[mawasile]

This pull request involves several changes to the internal/powerplatform directory, primarily focusing on the addition of two new files: set_bool_value_unknown_if_checksum_change_modifier.go and set_string_value_unknown_if_checksum_change_modifier.go. These files introduce new functions to modify boolean and string values to unknown if checksums change. Additionally, there are modifications to the resource_solution.go file to use these new functions and to make other minor changes.

Here are the most important changes:

Additions:

• internal/powerplatform/modifiers/set_bool_value_unknown_if_checksum_change_modifier.go: This new file introduces a function to modify boolean values to unknown if checksums change. It includes a method to calculate if the checksum has changed and another to modify the boolean value.
• internal/powerplatform/modifiers/set_string_value_unknown_if_checksum_change_modifier.go: This new file introduces a function to modify string values to unknown if checksums change. It includes a method to calculate if the checksum has changed and another to modify the string value.

Modifications:

• internal/powerplatform/services/solution/resource_solution.go: This file has several changes. The import statement was modified to remove the boolplanmodifier and stringplanmodifier packages and to use the new functions introduced in the set_bool_value_unknown_if_checksum_change_modifier.go and set_string_value_unknown_if_checksum_change_modifier.go files. The Schema function was updated to use these new functions. The Create and Update functions were modified to change the default value of SettingsFileChecksum from StringUnknown to StringNull. Other minor changes were made to improve error handling. [1] [2] [3] [4] [5] [6] [7]