Feat: Add Form Mainnet Chain (#927)

## Add new chain

> Template to provide information about the new chain. Only add extra
information in the bottom section. Ensure that the contracts are
deployed on the chain, if not deploy with
[safe-contracts](https://github.com/safe-global/safe-contracts). Only
**one** chain ID, **one** Safe version and **one** deployment type per
PR. The RPC will be taken from
[ethereum-lists/chains](https://github.com/ethereum-lists/chains). This
entire paragraph should be deleted.

Please fill the following form:

Provide the Chain ID (Only 1 chain id per PR).
- Chain_ID: 478

Provide RPC URL for the chain (should be able to query atleast 10
requests per minute for automatic PR check).

RPC_URL: https://rpc.form.network/http
Relevant information:
Add any other relevant information like blockexplorer, any annotation...

block-explorer: https://explorer.form.network/

-

src/assets/v1.3.0/compatibility_fallback_handler.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/create_call.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/gnosis_safe.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/gnosis_safe_l2.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/multi_send.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/multi_send_call_only.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/proxy_factory.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/sign_message_lib.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",

src/assets/v1.3.0/simulate_tx_accessor.json

@@ -93,6 +93,7 @@
     "420": "eip155",
     "424": "canonical",
     "466": "canonical",
+    "478": "canonical",
     "480": ["canonical", "eip155"],
     "570": "eip155",
     "588": "eip155",