chore(dips): add rpc and db feature flags to indexer-dips crate

[LNSD]

This pull request includes various changes to the crates/dips package to introduce feature flags and improve modularity. The key changes involve adding feature flags for optional dependencies, modifying the build script to conditionally compile based on features, and updating imports and module definitions accordingly.

Feature Flags and Dependencies:

• Added feature flags rpc and db in Cargo.toml to conditionally include dependencies ([crates/dips/Cargo.tomlR6-R35](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-271b41f6df2e65a887a3a18cd20536fb075df359339939c77d15843c117a070cR6-R35)).
• Updated dependencies in Cargo.toml to be optional based on the feature flags ([crates/dips/Cargo.tomlR6-R35](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-271b41f6df2e65a887a3a18cd20536fb075df359339939c77d15843c117a070cR6-R35)).

Build Script:

• Modified build.rs to conditionally compile proto files if the rpc feature is enabled ([[1]](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-708ee7d06e2e6e35b9419c852e467adcc59e77d759acd12bcd6988aab627dba7R5-R8), [[2]](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-708ee7d06e2e6e35b9419c852e467adcc59e77d759acd12bcd6988aab627dba7R23)).

Codebase Updates:

• Updated imports in database.rs and ipfs.rs to use async_trait from the async_trait crate instead of axum or tonic ([[1]](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-c8af91422fb1ed010565eac4fda150897bfbdba657084c76787d871da0fd27faL6-R6), [[2]](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-ca88c155ef694ceb70a734514fba168b1bd873c4efc481be50c7b8dab0b59aaaR6-L11)).
• Conditionally included modules database, proto, and server in lib.rs based on feature flags ([crates/dips/src/lib.rsR16-R22](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-43049e4db6e400dbf78fe60574626cb162e14dbb774b13f92bc9b05b68d08830R16-R22)).
• Added a conditional implementation of From<DipsError> for tonic::Status if the rpc feature is enabled ([crates/dips/src/lib.rsR171](https://github.com/graphprotocol/indexer-rs/pull/636/files#diff-43049e4db6e400dbf78fe60574626cb162e14dbb774b13f92bc9b05b68d08830R171)).