feat: derive serde for dispatchers

[ftupas]

Hello there, this small pr does the following

• derive Serde for contract and library dispatchers
• add test for dispatcher serde
• fix feat: implement Serde for dispatchers #3240

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This change is 

[orizi]

Reviewed 2 of 3 files at r1, all commit messages.
Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @ftupas)

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crates/cairo-lang-starknet/cairo_level_tests/contract_tests.cairo line 17 at r2 (raw file):

#[abi]
trait ITestContract {

if you are adding this only for the serde test - can you make this into a much simple abi?

Code quote:

#[abi]
trait ITestContract {

[ftupas]

Reviewed 2 of 3 files at r1, all commit messages.
Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @ftupas)

crates/cairo-lang-starknet/cairo_level_tests/contract_tests.cairo line 17 at r2 (raw file):

#[abi]
trait ITestContract {

if you are adding this only for the serde test - can you make this into a much simple abi?

Code quote:

#[abi]
trait ITestContract {

Thanks for the review and feedback @orizi ! I've just updated this to a simpler abi, much less clutter thanks!

[orizi]

Reviewed 2 of 3 files at r2, 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @ftupas)

[spapinistarkware]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @ftupas)