fix: avoid hardcoding pool types

[p0mvn]

Currently, we hardcode pool types as strings: https://github.com/osmosis-labs/osmosis-frontend/blob/71528ee78a8396561d070338c9a3462de82661fd/packages/web/server/queries/complex/pools/index.ts#L10-L17

Instead, these should be enum values imported from a single file rather than hardcoded in various locations

Acceptance Criteria

• Pool types consolidated in a single file
• Constans are imported everywhere else instead of being hardcoded