fix: fix refresh token flow in REST API OAuth

[sumitsum]

Description

• This PR adds the following config to REST API datasource when OAuth2.0 authentication is selected:
  • config to add client credentials on either header or body during refresh token flow.
  • if scope needs to be sent on refresh token flow.
• The configurations above are required because various OAuth servers behave differently and prefer different configurations.
• This PR also includes minor refactor to improve code debuggability (no change in code logic)
• Client side changes to add config on the REST API datasource page.

Fixes #10493

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Manual

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Test coverage results 🧪

🔴 Total coverage has decreased

// Code coverage diff between base branch:release and head branch: fix/fix_refresh_token_10493 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🔴	total	55.02 (-0.01)	36.35 (-0.02)	34.71 (0)	55.4 (-0.01)
🔴	app/client/src/pages/Editor/DataSourceEditor/RestAPIDatasourceForm.tsx	25 (-0.98)	14.08 (-1.3)	2.7 (-0.08)	27.66 (-1.23)

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[nidhi-nair]

LGTM, would recommend that the client adds these into a separate "Advanced" section since these settings won't usually be helpful for providers that follow the spec.

[nidhi-nair]

Needs a few UI changes

[sumitsum]

/ok-to-test sha=b023cbe

[github-actions]

Tests running at: https://github.com/appsmithorg/appsmith/actions/runs/1812674860.
Workflow: Appsmith External Integration Test Workflow.
Commit: b023cbe.
PR: 10875.

[sumitsum]

/ok-to-test sha=b023cbe

[github-actions]

Tests running at: https://github.com/appsmithorg/appsmith/actions/runs/1812919964.
Workflow: Appsmith External Integration Test Workflow.
Commit: b023cbe.
PR: 10875.

[github-actions]

UI Performance test run logs and artifacts: https://github.com/appsmithorg/appsmith/actions/runs/1812919964.
Commit: b023cbe.
Results:

Click to view performance test results

	Run 1	Run 2	Run 3	Run 4	Run 5	Median	Mean	SD.Sample	SD.Population
Edit input
scripting	439.58	404.47	293.09	331.24	295.43	331.24	352.76	18.76	16.78
painting	41.54	12.87	15.16	19.98	46.18	19.98	27.15	57.31	51.27
rendering	21.58	25.31	14.01	18.62	17.12	18.62	19.33	22.35	19.97
Clear input
scripting	782.67	726.6	729.57	722.94	746.32	729.57	741.62	3.32	2.97
painting	6.58	7.07	14.02	14.51	5.67	7.07	9.57	45.14	40.33
rendering	215.55	215.66	179.81	192.06	187.43	192.06	198.1	8.36	7.48
Edit input again
scripting	277.81	646.32	289.31	635.28	316.99	316.99	433.14	43.90	39.26
painting	5.65	14.97	22.7	5.2	18.98	14.97	13.5	58.22	52.07
rendering	21.73	20.01	22.26	24.08	25.45	22.26	22.71	9.29	8.32