Change "Tip" language to "Contribution" language and remove "One-time" language

[Miyayes]

Description

• [ ] Replace "Tip" language with "Contribution" language
• [ ] Gracefully remove "One-time" language (careful if it introduces ambiguity)

General rules:

1. Replace "Tip" with "Contribution" where it makes sense (note pluralization)
2. Monthly Tips --> Monthly Contributions
3. Tipped --> Contributed
4. Send Tip --> Send Contribution

Do not change "Tip" on inline tip buttons, and text specifically related to inline Tip buttons.

[Miyayes]

Target: 1.52.x alongside the Tip Banner 3.0.

[LaurenWags]

Verified with

Brave | 1.52.108 Chromium: 114.0.5735.26 (Official Build) beta (x86_64)
-- | --
Revision | 7075cbb66f0542ac3e01ddfde6b813e7d61118a5-refs/branch-heads/5735@{#454}
OS | macOS Version 13.3.1 (a) (Build 22E772610a)

Additional contribution/banner testing can be found under https://github.com/brave/brave-browser/issues/28148.

Verified UI as per https://github.com/brave/brave-core/pull/18027#issue-1665163819.

brave://rewards	brave://rewards	Panel	Panel	Contribution banner	Monthly Statement

Per https://github.com/brave/brave-browser/issues/29603#issue-1660994244, confirmed "Tip" wording remains in place for in-line tip buttons and text related to in-line tip buttons.

brave://settings/rewards (Rewards disabled)	brave://settings/rewards (Rewards enabled)	brave://rewards	Twitter	GitHub	Reddit