Request for Support for Custom Submit API Nodes in Lace Wallet

[mrsqurriel]

Issue Description:
I am currently using Lace wallet, and I have encountered limitations when attempting to use a custom submit API node. From my understanding, Lace only supports a predefined set of submit API providers and locally installed submit APIs. As a user who wishes to interact with a trusted custom node, I would like to understand why Lace restricts the ability to configure and use custom submit API endpoints.

Steps to Reproduce:
Attempt to configure Lace wallet to use a custom submit API node.
Example of a URL: https://mytrustednode/api/submit/tx
Encounter issues with connecting to trusted custom nodes.

Expected Behavior:
Users should be able to set their own trusted submit API endpoints for transaction submission.
Lace should provide an option to add custom nodes that are trusted, enabling more flexibility and control over transaction submission.

Actual Behavior:
Lace currently restricts users to a predefined set of submit API providers.
There is no option to configure a custom node that I trust, limiting the flexibility for users who want to interact with their own submit API.

Test Results:
Through testing and help from users on the Cardano Forum, we managed to circumvent using Local Proxy Method (This may not work well with dapps) and Manifest File Modification (Unsafe Method).

Questions:
Why is it that we cannot use custom submit API nodes that we trust in Lace?
Is there any way for Lace to allow users to configure custom submit APIs in a secure way?
Would it be possible for Lace to support more flexibility for trusted custom nodes without the need for unsafe workarounds like manipulating the manifest file?