Fix #34

[anthonyprintup]

This PR fixes issue #34.

Detailed description:

• added a new import ida_typeinf for typeinf related APIs,
• added a new helper function get_existing_enum_values which checks if an enum already exists and parses its values using the IDA API (ida_typeinf.get_named_type, ida_typeinf.idc_print_type),
• add_enums will now check for existing enum values before parsing the provided hash list,
• add_enums now manually corrects strings with dots in their names (e.g. ntdll.dll -> ntdll_dll),
• add_enums now uses ida_name.get_name_ea to check if a name already exists in the database (previously used ida_enum.add_enum_member which checked this automatically)
• add_enums no longer expects a 3rd function parameter because the enum size now depends on the database type or the algorithm size (64-bit databases will always generate 64-bit enums),
• add_enums: replaced the method used when creating an enum (massive performance improvements); using ida_typeinf.idc_parse_types and ida_typeinf.import_type.

Possible (but unlikely) bugs:

• get_existing_enum_values will not parse values properly on expected integer bases (e.g. if for some reason the values aren't in decimal or hexadecimal form),
• because we no longer use ida_enum.add_enum_member to append enum members we lose some internal corrections that IDA performs on the enum names (e.g. replacing dots with underscores); this has to be corrected manually from now on.

Disclaimer:

I've only tested the plugin on two samples (one 32-bit and one 64-bit). Strings with invalid names (e.g. -path) haven't been tested yet, but should work (look at #31). TLDR; more testing required before we can push a release.

[anthonyprintup]

Added support for IDA 8.0 by using ida_enum.get_enum_member_by_name to check for enum names.

[anthonyprintup]

I've only tested the plugin on two samples (one 32-bit and one 64-bit). Strings with invalid names (e.g. -path) haven't been tested yet, but should work (look at https://github.com/OALabs/hashdb-ida/pull/31).

Confirmed to be working properly in all instances. All tests passed (IDA 8.0, Python 3.10.6) and ready to merge.